The local orchestra has been invited to play at a festival. There are 111 members of the orchestra and 6 are licensed to drive large multi-passenger vehicles. Busses hold 25 people but are much more expensive to rent. Passenger vans hold 12 people. make a system of equations to find the smallest number of busses the orchestra can rent. Let x= the number of busses and y= the number of vans make an equation representing the number of vehicles needed. __________ make an equation representing the total number of seats in vehicles for the orchestra members. __________ Solve the system of equations. How many busses does the orchestra need to rent? ____________ How many 12-passenger vans does the orchestra need to rent? ____________

Answers

Answer 1

- Make an equation representing the number of vehicles needed.

We have six drivers so

x + y ≤ 6

That's not really an equation; it's an inequality.  We want to use all our drivers so we can use the small vans, so

x + y = 6

- Make an equation representing the total number of seats in vehicles for the orchestra members.

s = 25x + 12y

That's how many seats total; it has to be at least 111 so again an inequality,

25x + 12y ≥ 111

We solve it like a system of equations.  

x + y = 6

y = 6 - x

111 = 25x + 12y = 25x + 12(6-x)

111 = 25x + 72 - 12x

111 - 72 = 13 x

39 = 13 x

x = 3

Look at that,  it worked out exactly.  It didn't have to.

y = 6 - x = 3

Answer: 3 buses, 3 vans

Answer 2

Using a System of equations, the number of buses and vans required are 3 respectively.

Using the system of equations :

Total number of buses :

b + v ≤ 6 - - - - (1)

Total number of passengers :

25b + 12v ≥ 111 - - - - (2)

From (1)

b = 6 - v - - - - - (3)

Substitute (3) into (2)

25(6-v) + 12v = 111

150 - 25v + 12v = 111

-13v = 111 - 150

-13v = - 39

v = 39/13

v = 3

From (3)

b = 6 - 3

b = 3

Hence, the number of vans and buses required are 3 and 3 respectively.

Learn more : https://brainly.com/question/16144029


Related Questions

The product of an initial investment, I, and the quantity of the sum of 1 and the annual interest rate, r, raised to the power of n, the number of years of the investment, is equal to M, the current amount of money in an investment account. If an initial investment of $1,423.00 is made to an account with an annual interest rate of 2%, what will be the value of M after 3 years? Round to the nearest cent. A. $1,510.10 B. $1,339.32 C. $1,480.49 D. $1,508.38

Answers

Answer:

  A. $1,510.10

Step-by-step explanation:

Fill in the given numbers and do the arithmetic.

  M = I·(1+r)^n

  M = $1423.00·(1 +.02)^3 = $1510.099

  M ≈ $1510.10

A random sample of size 100 was taken from a population. A 94% confidence interval to estimate the mean of the population was computed based on the sample data. The confidence interval for the mean is: (107.62, 129.75). What is the z-value that was used in the computation. Round your z-value to 2 decimal places. Select one: A. 1.45 B. 1.55 C. 1.73 D. 1.88 E. 1.96 E-mail fraud (phishing) is becoming an increasing problem for users of the internet. Suppose that 70% of all internet users experience e-mail fraud. If 50 internet users were randomly selected, what is the probability that no more than 25 were victims of e-mail fraud? Answer:

Answers

Answer:

Step-by-step explanation:

1) The z value was determined using a normal distribution table. From the normal distribution table, the corresponding z value for a 94% confidence interval is 1.88

The correct option is D

2) if 70% of all internet users experience e-mail fraud. It means that probability of success, p

p = 70/100 = 0.7

q = 1 - p = 1 - 0.7 = 0.3

n = number of selected users = 50

Mean, u = np = 50×0.7 = 35

Standard deviation, u = √npq = √50×0.7×0.3 = 3.24

x = number of internet users

The formula for normal distribution is expressed as

z = (x - u)/s

We want to determine the probability that no more than 25 were victims of e-mail fraud. It is expressed as

P(x lesser than or equal to 25)

The z value will be

z = (25- 35)/3.24 = - 10/3.24 = -3.09

Looking at the normal distribution table, the corresponding z score is 0.001

P(x lesser than or equal to 25) = 0.001

The cycle time for trucks hauling concrete to a highway construction site is uniformly distributed over the interval 50 to 70 minutes. What is the conditional probability that the cycle time is no more than 65 minutes if it is known that the cycle time exceeds 55 minutes?

Answers

Answer:

2/3=0.6667

Step-by-step explanation:

Let X be the cycle time for  trucks hauling concrete to a highway construction site

Given that X is U(50,70)

Hence pdf of X is

[tex]f(x) = \frac{1}{20} ,50<x<70[/tex]

Let A be the event that cycle time is no more than 65 minutes and

B the event cycle time exceeds 55 minutes

Required probability

=  the conditional probability that the cycle time is no more than 65 minutes if it is known that the cycle time exceeds 55 minutes

= P(A/B)

=[tex]\frac{P(A\bigcapB)}{P(B)} \\=\frac{P(55<x<65)}{P(X>55)} \\=\frac{65-55}{70-55} \\=\frac{2}{3}[/tex]

Suppose that we are testing a coin to see if it is fair, so our hypotheses are: H0: p = 0.5 vs Ha: p ≠ 0.5. In each of (a) and (b) below, use the "Edit Data" option on StatKey to find the p-value for the sample results and give a conclusion in the test. a. We get 56 heads out of 100 tosses. b. We get 560 heads out of 1000 tosses. c. Compare the sample proportions in parts (a) and (b). Compare the p-values. Why are the p-values so different?

Answers

For testing if a coin is fair, a binomial test is used to compare the observed heads to what's expected under a fair coin scenario. Differences in p-values for the same sample proportion across different sample sizes are due to the increased precision of larger samples.

In hypothesis testing, when we want to determine whether a coin (or in this case, a hypothetical lizard) is fair, we employ a binomial test. This test assesses the number of 'successes' (heads in our case), comparing it to what we would expect under the null hypothesis of p=0.5, indicating a fair coin.

For part (a), where we get 56 heads out of 100 tosses, we would calculate the p-value by looking at both the proportion of heads obtained and the standard error for a binomial distribution. Although not calculated here directly, if this p-value is less than the chosen significance level, typically 0.05, we reject the null hypothesis, concluding the coin is not fair.

For part (b), getting 560 heads out of 1000 tosses yields the same sample proportion as part (a). However, the larger sample size increases the power of the test, often resulting in a smaller p-value if the observed proportion is different from the expected 0.5.

Comparing p-values from (a) and (b) reveals that despite having the same sample proportions, the p-values differ due to the sample sizes. Larger sample sizes yield more precise estimates of the population proportion, thus potentially resulting in smaller p-values for the same sample proportion deviation from the null hypothesis.

Which of the following functions computes a value such that 2.5% of the area under the standard normal distribution lies in the upper tail defined by this value? ○ 0 ° ○ a.-NORMSINV(0.975) b.-NORM·S.INV(0.05) C.-NORM.S-INV(0.95) d.-NORMSINV(0.025)

Answers

Answer:

a) NORM.S.INV(0.975)

Step-by-step explanation:

1) Some definitions

The standard normal distribution is a particular case of the normal distribution. The parameters for this distribution are: the mean is zero and the standard deviation of one. The random variable for this distribution is called Z score or Z value.

NORM.S.INV Excel function "is used to find out or to calculate the inverse normal cumulative distribution for a given probability value"

The function returns the inverse of the standard normal cumulative distribution(a z value). Since uses the normal standard distribution by default the mean is zero and the standard deviation is one.

2) Solution for the problem

Based on this definition and analyzing the question :"Which of the following functions computes a value such that 2.5% of the area under the standard normal distribution lies in the upper tail defined by this value?".

We are looking for a Z value that accumulates 0.975 or 0.975% of the area on the left and by properties since the total area below the curve of any probability distribution is 1, then the area to the right of this value would be 0.025 or 2.5%.

So for this case the correct function to use is: NORM.S.INV(0.975)

And the result after use this function is 1.96. And we can check the answer if we look the picture attached.

A new shopping mall is considering setting up an information desk manned by one employee. Based upon information obtained from similar information desks, it is believed that people will arrive at the desk at a rate of 20 per hour. It takes an average of 2 minutes to answer a question. It is assumed that the arrivals follow a Poisson distribution and answer times are exponentially distributed. (a) find the probability that the employee is idle. (b) Find the proportion of the time that the employee is busy. (c) Find the average number of people receiving and waiting to receive some information. (d) Find the average number of people waiting in line to get some information. (e) Find the average time a person seeking information spends in the system. (f) Find the expected time a person spends just waiting in line to have a question answered (time in the queue).

Answers

Answer:

a) [tex]P=1-\frac{\lambda}{\mu}=1-\frac{20}{30}=0.33[/tex] and that represent the 33%

b) [tex]p_x =\frac{\lambda}{\mu}=\frac{20}{30}=0.66[/tex]

c) [tex]L_s =\frac{20}{30-20}=\frac{20}{10}=2 people[/tex]

d) [tex]L_q =\frac{20^2}{30(30-20)}=1.333 people[/tex]

e) [tex]W_s =\frac{1}{\lambda -\mu}=\frac{1}{30-20}=0.1hours[/tex]

f) [tex]W_q =\frac{\lambda}{\mu(\mu -\lambda)}=\frac{20}{30(30-20)}=0.0667 hours[/tex]

Step-by-step explanation:

Notation

P represent the probability that the employee is idle

[tex]p_x[/tex] represent the probability that the employee is busy

[tex]L_s[/tex] represent the average number of people receiving and waiting to receive some information

[tex]L_q[/tex] represent the average number of people waiting in line to get some information

[tex]W_s[/tex] represent the average time a person seeking information spends in the system

[tex]W_q[/tex] represent the expected time a person spends just waiting in line to have a question answered

This an special case of Single channel model

Single Channel Queuing Model. "That division of service channels happen in regards to number of servers that are present at each of the queues that are formed. Poisson distribution determines the number of arrivals on a per unit time basis, where mean arrival rate is denoted by λ".

Part a

Find the probability that the employee is idle

The probability on this case is given by:

In order to find the mean we can do this:

[tex]\mu = \frac{1question}{2minutes}\frac{60minutes}{1hr}=\frac{30 question}{hr}[/tex]

And in order to find the probability we can do this:

[tex]P=1-\frac{\lambda}{\mu}=1-\frac{20}{30}=0.33[/tex] and that represent the 33%

Part b

Find the proportion of the time that the employee is busy

This proportion is given by:

[tex]p_x =\frac{\lambda}{\mu}=\frac{20}{30}=0.66[/tex]

Part c

Find the average number of people receiving and waiting to receive some information

In order to find this average we can use this formula:

[tex]L_s= \frac{\lambda}{\lambda -\mu}[/tex]

And replacing we got:

[tex]L_s =\frac{20}{30-20}=\frac{20}{10}=2 people[/tex]

Part d

Find the average number of people waiting in line to get some information.

For the number of people wiating we can us ethe following formula"

[tex]L_q =\frac{\lambda^2}{\mu(\mu-\lambda)}[/tex]

And replacing we got this:

[tex]L_q =\frac{20^2}{30(30-20)}=1.333 people[/tex]

Part e

Find the average time a person seeking information spends in the system

For this average we can use the following formula:

[tex]W_s =\frac{1}{\lambda -\mu}=\frac{1}{30-20}=0.1hours[/tex]

Part f

Find the expected time a person spends just waiting in line to have a question answered (time in the queue).

For this case the waiting time to answer a question we can use this formula:

[tex]W_q =\frac{\lambda}{\mu(\mu -\lambda)}=\frac{20}{30(30-20)}=0.0667 hours[/tex]

Final answer:

To find the probability that the employee is idle, use the formula P(idle) = e^(-λ) where λ = arrival rate * service time. To find the proportion of the time the employee is busy, subtract the probability that the employee is idle from 1. To find the average number of people receiving and waiting to receive information, use the formulas arrival rate * service time and arrival rate * average time spent in system. To find the average time a person spends seeking information and just waiting in line, add the average time to answer a question to the average waiting time.

Explanation:

To find the probability that the employee is idle, we need to find the rate at which people arrive at the information desk and the average time it takes to answer a question. The rate at which people arrive follows a Poisson distribution with a rate of 20 per hour. This means that the average time between arrivals is 1/20 of an hour. The average time to answer a question is 2 minutes, which is equivalent to 2/60 = 1/30 of an hour.

The probability that the employee is idle can be calculated using the formula:

P(idle) = e^(-λ) where λ = arrival rate * service time

Substituting the given values:

P(idle) = e^(-(1/20)(1/30))

P(idle) = e^(-1/600) ≈ 0.998335

Therefore, the probability that the employee is idle is approximately 0.998335.

(b) To find the proportion of the time the employee is busy, we can subtract the probability that the employee is idle from 1:

P(busy) = 1 - P(idle)

P(busy) = 1 - 0.998335 ≈ 0.001665

Therefore, the proportion of the time the employee is busy is approximately 0.001665.

(c) The average number of people receiving information can be calculated using the formula:

Average number of people receiving information = arrival rate * service time

Substituting the given values:

Average number of people receiving information = 20 * (1/30)

Average number of people receiving information = 2/3 ≈ 0.6667

Therefore, the average number of people receiving information is approximately 0.6667.

(d) The average number of people waiting in line to get information can be calculated using Little's Law:

Average number of people waiting in line = arrival rate * average time spent in system

The average time spent in the system can be calculated by adding the average time to answer a question to the average waiting time:

Average time spent in the system = average time to answer a question + average waiting time

The average waiting time can be calculated using Little's Law:

Average waiting time = average number of people waiting in line / arrival rate

Substituting the given values:

Average waiting time = (1/20) / (1/30) = 3/2 = 1.5 minutes

Average time spent in the system = 2 minutes + 1.5 minutes = 3.5 minutes

Substituting the values into Little's Law:

Average number of people waiting in line = 20 * (3.5/60) = 1.1667

Therefore, the average number of people waiting in line to get information is approximately 1.1667.

(e) The average time a person spends in the system can be calculated by adding the average time to answer a question to the average waiting time:

Average time in system = average time to answer a question + average waiting time = 2 minutes + 1.5 minutes = 3.5 minutes

Therefore, the average time a person seeking information spends in the system is 3.5 minutes.

(f) The expected time a person spends just waiting in line to have a question answered can be calculated using Little's Law:

Expected time in queue = average number of people waiting in line / arrival rate

Substituting the values:

Expected time in queue = (1/20) minutes / (1/30) = 30/20 = 1.5 minutes

Therefore, the expected time a person spends just waiting in line to have a question answered is 1.5 minutes.

Learn more about Probability here:

https://brainly.com/question/22962752

#SPJ3

Let A and B be n x n matrices.

The determinant of A is the product of the diagonal entries in A. Select the correct choice below​ and, if​ necessary, fill in the answer box to complete your choice.

A.

The statement is true because the determinant of any triangular matrix A is the product of the entries on the main diagonal of A.

B.

The statement is false because the determinant of the 2×2 matrix A = __ is not equal to the product of the entries on the main diagonal of A.

​(Type an integer or simplified fraction for each matrix​element.)

C.

The statement is true because the determinant of any square matrix A is the product of the entries on the main diagonal of A.

Answers

Final answer:

The statement regarding the determinant of a square matrix A being the product of its diagonal entries is incorrect. The determinant of a 2×2 matrix is calculated as the product of diagonal entries minus the product of off-diagonal entries.

Explanation:

The determinant of a square matrix A is not always the product of the diagonal entries in A. For instance, a 2×2 matrix has the determinant given by det(A) = a11a22 - a12a21, which involves the product of the diagonal entries minus the product of the off-diagonal entries. Therefore, the correct choice is:

B. The statement is false because the determinant of the 2×2 matrix A = [[a, b], [c, d]] is not equal to the product of the entries on the main diagonal of A. In fact, the determinant is ad - bc.

Example: For matrix A = [[1,2], [3,4]], the determinant is 1×4 - 2×3, which equals -2, not the product of the diagonal entries (1 and 4), which would be 4.

Bob and Sally mortgage payment increases to $1632.00. Their roof starts to leak and they need to replace it. They budget 500$ per month (replace the old student loan charge with roof expense).

Answers

Answer:

...

Step-by-step explanation:

A family raised $1000 for their initial investment. If they invest the money in an account that earns 5% interest compounded annually, what will be the value of their investment at the end of 15 years?

The exponential function that expresses the amount of the investment as a function of time when compounded annually is: A(t)=P(1+r)^t

1. Evaluate function: A(15) =

2. Amount of interest earned in dollars:

3. Use the trace function to determine the value of the investment after 18 years.

4. Use the table function to determine how many years it will take for the investment to double.

5. How much more interest would be earned after 15 years if the interest rate were 5.5%?

If the investment is compounded more often than annually, the exponential function becomes ( ) (1 )nt r At P n = + , where n is the number of times the interest is compounded annually. Notice that if n = 1, the formula simplifies to the one used above.


6. If the family’s initial investment is the same with a 5% interest rate, but now it is compounded monthly, what is the value after 15 years of the investment?

7. How many years does it take the investment to double?

8. How much interest would be earned if the initial investment was $1,500 compounded monthly at the same 5% interest rate? How does this compare to the interest earned with the original $1,000 investment?

Answers

Answer:

8 or 3

Step-by-step explanation:

Marie sees a leather jacket kn sale for $73.00. The sign says 20% off. How much was the jacket originally? ​

Answers

Answer:

It was originally $91.25

Which system of linear equations is graphed below

Answers

Answer:

D

Step-by-step explanation:

At a large department store, the average number of years of employment for a cashier is 5.7 with a standard deviation of 1.8 years, and the distribution is approximately normal. If an employee is picked at random, what is the probability that the employee has worked at the store for over 10 years? 99.2% 0.8% 49.2% 1.7%

Answers

Answer:

option 0.8%

Step-by-step explanation:

Data provided in the question:

Mean = 5.7 years

Standard deviation, s = 1.8 years

Now,

P(the employee has worked at the store for over 10 years)

= P(X > 10 years)

= [tex]P (Z > \frac{X-Mean}{\sigma})[/tex]

or

= [tex]P (Z > \frac{10-5.7}{1.8})[/tex]

= P (Z > 2.389 )

or

= 0.008447     [from standard  z table]

or

= 0.008447 × 100% = 0.84% ≈ 0.8%

Hence,

the correct answer is option 0.8%

Final answer:

To find the probability that an employee has worked at a large department store for over 10 years, we can use the z-score formula and a standard normal distribution table or calculator.

Explanation:

To find the probability that an employee has worked at the store for over 10 years, we can use the z-score formula:

z = (x - μ) / σ

where x is the value we are interested in (10 years), μ is the mean (5.7 years), and σ is the standard deviation (1.8 years).

Plugging in the values, z = (10 - 5.7) / 1.8 = 2.39

Using a standard normal distribution table or a calculator, we can find that the probability of a z-score greater than 2.39 is approximately 0.008, or 0.8%.

Learn more about Probability here:

https://brainly.com/question/32117953

#SPJ3

Seventy-six percent of products come off the line within product specifications. Your quality control department selects 15 products randomly from the line each hour. Looking at the binomial distribution, if fewer than how many are within specifications would require that the production line be shut down (unusual) and repaired?A. Fewer than 12
B. Fewer than 11
C. Fewer than 10
D. Fewer than 9.

Answers

Answer:

A

Step-by-step explanation:

change 76% to decimal and multiply by 15

.76*15 = 11.4

11.4 is fewer than 12.

A toy company is modeling a real home as a doll house. They decide to use a 2/3 inch to 1 foot scale, the traditional scale for doll house built in the 20th century. If the actual house is 30 feet high, how high will the dollhouse be in inches?

Answers

Answer:

20 inches

Step-by-step explanation:

Take 2/3 of an inch 30 times.

The height of the model is then 30 times 2/3 inches = 10*2 = 20 inches

The highway fuel economy of a 2016 Lexus RX 350 FWD 6-cylinder 3.5-L automatic 5-speed using premium fuel is a normally distributed random variable with a mean of μ = 20.50 mpg and a standard deviation of σ = 3.00 mpg. (a) What is the standard error of X¯¯¯X¯ , the mean from a random sample of 36 fill-ups by one driver? (Round your answer to 4 decimal places.) Standard error of X¯¯¯X¯ (b) Within what interval would you expect the sample mean to fall, with 99 percent probability? (Round your answers to 4 decimal places.) The interval is from to

Answers

Answer:

a) Standard error = 0.5

b) 99% Confidence interval:  (19.2125,21.7875)

Step-by-step explanation:

We are given the following in the question:

Population mean =  20.50 mpg

Sample standard deviation = 3.00 mpg

Sample size , n = 36

Standard Error =

[tex]=\displaystyle\frac{\sigma}{\sqrt{n}} = \frac{3}{\sqrt{36}} = 0.5[/tex]

99% Confidence interval:

[tex]\mu \pm z_{critical}\frac{\sigma}{\sqrt{n}}[/tex]

Putting the values, we get,

[tex]z_{critical}\text{ at}~\alpha_{0.01} = \pm 2.575[/tex]

[tex]20.50 \pm 2.575(\displaystyle\frac{3}{\sqrt{36}})= 20.50 \pm 1.2875 = (19.2125,21.7875)[/tex]

Final answer:

The standard error of the mean from 36 fill-ups of the 2016 Lexus RX350 is 0.50 miles per gallon. The sample mean, with 99% probability, is expected to fall within the interval from 18.714 to 22.286 miles per gallon.

Explanation:

The standard error (SE) of the mean from a sample of 36 fill-ups for the Lexus RX 350 is calculated by dividing the standard deviation by the square root of the sample size. In this case, the standard deviation (σ) is 3.00 mpg and the sample size (n) is 36.

The formula for the standard error is SE = σ / √n = 3.00 / √36 = 0.50 mpg (rounded to four decimal places).

To find the interval in which the sample mean is expected to fall with 99 percent probability, we use the concept of Z-scores, which relate the mean, standard error, and the probability. For a 99% probability, the Z-score (z) is approximately 2.576. The interval can be found using the following formula: μ ± z * SE, replacing the symbols with the values calculated, 20.50 ± 2.576 * 0.50 which results in the interval (18.714, 22.286) mpg (rounded to four decimal places).

Learn more about Statistics here:

https://brainly.com/question/31538429

#SPJ3

A researcher developing scanners to search for hidden weapons at airports has concluded that a new device is significantly better than the current scanner. He made this decision based on a test using a = 0.05. Would he have made the same decision at a = 0.10? How about a = 0.01? Explain.

Answers

Answer:

He can make the same decision at a = 0.10, but he may not make the same decision at a = 0.01

Step-by-step explanation:

In hypothesis tests, critical regions are ranges of the distributions where the values represent statistically significant results. Analysts define the size and location of the critical regions by specifying both the significance level (alpha) and whether the test is one-tailed or two-tailed.

As the significance level gets bigger, the range of the critical region increases.

Therefore significant results at lower significance levels are still significant at higher significance levels. Thus significant result at a=0.05 is always significant at a=0.10

But  significant result at a=0.05 may not be significant at a=0.01 since critical region shrinks, therefore the result may not fall in the critical region at a=0.01

A supervisor records the repair cost for 25 randomly selected dryers. A sample mean of $93.36 and standard deviation of $19.95 are subsequently computed. Determine the 98% confidence interval for the mean repair cost for the dryers. Assume the population is approximately normal.

Answers

Answer:

The 98% confidence interval for the mean repair cost for the dryers is (83.4161, 103.3039).

Step-by-step explanation:

We have a small sample size n = 25, [tex]\bar{x} = 93.36[/tex] and s = 19.95. The confidence interval is given by  [tex]\bar{x}\pm t_{\alpha/2}(\frac{s}{\sqrt{n}})[/tex] where [tex]t_{\alpha/2}[/tex] is the [tex]\alpha/2[/tex]th quantile of the t distribution with n - 1 = 25 - 1 = 24 degrees of freedom. As we want the 98% confidence interval, we have that [tex]\alpha = 0.02[/tex] and the confidence interval is [tex]93.36\pm t_{0.01}(\frac{19.95}{\sqrt{25}})[/tex] where [tex]t_{0.01}[/tex] is the 1st quantile of the t distribution with 24 df, i.e., [tex]t_{0.01} = -2.4922[/tex]. Then, we have [tex]93.36\pm (-2.4922)(\frac{19.95}{\sqrt{25}})[/tex] and the 98% confidence interval is given by (83.4161, 103.3039).

Answer:

Step-by-step explanation:

Our aim is to determine a 98% confidence interval for the mean repair cost for the dryers

Number of samples. n = 25

Mean, u = $93.36

Standard deviation, s = $19.95

For a confidence level of 98%, the corresponding z value is 2.33. This is determined from the normal distribution table.

We will apply the formula,

Confidence interval

= mean ± z × standard deviation/√n

It becomes

93.36 ± 2.33 × 19.95/√25

= 93.36 ± 2.33 × 3.99

= 93.36 ± 9.2967

The lower boundary of the confidence interval is 93.36 - 9.2967 =84.0633

The upper boundary of the confidence interval is 93.36 + 9.2967 = 102.6567

Therefore, with 98% confidence interval, the mean repair costs for the dryers is between $84.0633 and $102.6567

The vertical angle to the top of a flagpole from point A on the ground is observed to be 37°11'. The observer walks 17 m directly away from point A and the flagpole to point B and finds the new angle to be 25°43'. What is the approximate height of the flagpole?

Answers

Answer:

22m

Step-by-step explanation:

Let height of flagpole=h

AB==17 m

[tex]\angle CAD=37^{\circ}11'=37+\frac{11}{60}=37.183^{\circ}[/tex](1 degree= 60 minute)

[tex]\angle B=25^{\circ}43'=25+\frac{43}{60}=25.72^{\circ}[/tex]

We have to find the approximate height of the flagpole.

In triangle CDA,

[tex]\frac{CD}{DA}=tan\theta=\frac{Perpendicular\;side}{Base}[/tex]

[tex]\frac{h}{DA}=tan37.183^{\circ}[/tex]

[tex]h=DA(0.759)[/tex]

In triangle CDB,

[tex]tan 25.72^{\circ}=\frac{CD}{DB}[/tex]

[tex]0.482=\frac{h}{DA+17}[/tex]

[tex]0.482DA+8.194=h[/tex]

Substitute the value

[tex]0.482DA+8.194=0.759DA[/tex]

[tex]8.194=0.759DA-0.482DA[/tex]

[tex]8.194=0.277DA[/tex]

[tex]DA=\frac{8.194}{0.277}=29.58[/tex]

Substitute the value

[tex]h=29.58 \times 0.759=22.45 m\approx 22m[/tex]

Hence, the height of the flagpole=22 m

The approximate height of the flagpole is 21.33 meters, calculated using trigonometry and the observed angles and distances.

To find the height of the flagpole, we can use trigonometry, specifically the tangent function, along with the given angles and the distance from the observer's initial position to the flagpole.

Step 1:

Calculate the tangent of the observed angles:

Let (h) be the height of the flagpole.

For the first observation:

[tex]\[ \tan(37^\circ 11') = \frac{h}{d} \][/tex]

For the second observation:

[tex]\[ \tan(25^\circ 43') = \frac{h}{d + 17} \][/tex]

Step 2:

Solve for (h):

First, convert the angles to decimal degrees:

[tex]\[ 37^\circ 11' = 37 + \frac{11}{60} \approx 37.18^\circ \][/tex]

[tex]\[ 25^\circ 43' = 25 + \frac{43}{60} \approx 25.72^\circ \][/tex]

Now, substitute the angles into the tangent equations:

[tex]\[ \tan(37.18^\circ) = \frac{h}{d} \][/tex]

[tex]\[ \tan(25.72^\circ) = \frac{h}{d + 17} \][/tex]

Step 3:

Solve the equations for (h):

[tex]\[ h = d \times \tan(37.18^\circ) \][/tex]

[tex]\[ h = (d + 17) \times \tan(25.72^\circ) \][/tex]

Step 4:

Set the expressions equal to each other:

[tex]\[ d \times \tan(37.18^\circ) = (d + 17) \times \tan(25.72^\circ) \][/tex]

Step 5:

Solve for (d):

[tex]\[ d = \frac{17 \times \tan(25.72^\circ)}{\tan(37.18^\circ) - \tan(25.72^\circ)} \][/tex]

Step 6:

Calculate the value of (d) and then use it to find (h):

[tex]\[ d \approx 27.83 \text{ meters} \][/tex]

[tex]\[ h = 27.83 \times \tan(37.18^\circ) \][/tex]

Step 7:

Calculate (h):

[tex]\[ h \approx 27.83 \times 0.7656 \][/tex]

[tex]\[ h \approx 21.33 \text{ meters} \][/tex]

Therefore, the approximate height of the flagpole is 21.33 meters.

Which of the following is the purpose of a confidence interval for the fitted (predicted value) from a
regression model?

A) To estimate the value of a future observation for a given value of x.

B) To estimate the population mean of Y for a given value of x

C) To estimate the population slope of the regression model

D) To estimate the sample mean of Y for a given value of x.

Answers

Answer: option A is correct

Step-by-step explanation:

the prediction interval is to cover a “moving target”, the random future value of y,

while the confidence interval is to cover the “fixed target”,

the average (expected) value of y, E(y).

The surface of a hill is modeled by z = 100 − 4 x 2 − 2 y 2 . When a group of hikers reach the point (-3,-2,56) it begins to snow. They decide to descend the hill as rapidly as possible. Which of the following vectors points in the direction they should start their descent? < 24 , 8 > < 24 x , 8 y > < − 24 x , − 8 y > < − 24 , − 8 > None of the above

Answers

Answer:

(-24, -8)

Step-by-step explanation:

Let us recall that when we have a function f

[tex]\large f:\mathbb{R}^2\rightarrow \mathbb{R}\\f(x,y)=z[/tex]

if the gradient of f at a given point (x,y) exists, then the gradient of f at this point (x,y) gives the direction of maximum rate of increasing and minus the gradient of f at this point gives the direction of maximum rate of decreasing. That is

[tex]\large \nabla f=(\frac{\partial f}{\partial x},\frac{\partial f}{\partial y})[/tex]

at the point (x,y) gives the direction of maximum rate of increasing

[tex]\large -\nabla f[/tex]

at the point (x,y) gives the direction of maximum rate of decreasing

In this case we have

[tex]\large f(x,y)=100-4x^2-2y^2[/tex]

and we want to find the direction of fastest speed of decreasing at the point (-3,-2)

[tex]\large \nabla f(x,y)=(-8x,-4y) \Rightarrow -\nabla f=(8x,4y)[/tex]

at the point (-3,-2) minus the gradient equals

[tex]\large -\nabla f(-3,-2)=(-24,-8)[/tex]

hence the vector (-24,-8) points in the direction with the greatest rate of decreasing, and they should start their descent in that direction.

If Data A has a correlation coefficient of r = - 0.991, and Data B has a correlation coefficient of r = 0.991, which correlation is correct? a. Data A has a stronger linear correlation than Data B. b. Data A and Data B have the same strength in linear correlation. c. Data A has a weaker linear correlation than Data B.

Answers

Answer:

Option B) Data A and Data B have the same strength in linear correlation.

Step-by-step explanation:

Correlation:

Correlation is a technique that help us to find or define a relationship between two variables. It is a measure of linear relationship between two quantities. A positive correlation means that an increase in one quantity leads to an increase in another quantity A negative correlation means with increase in one quantity the other quantity decreases. +1 tells about a a perfect positive linear relationship and −1 indicates a perfect negative linear relationship.

Data A correlation = -0.991

Data B correlation = 0.991

Data A and data B have same strength of correlation but they are opposite to each other. There absolute value is same but the data A shows negative correlation and data B shows positive correlation. Data A shows indirect or inverse linear relationship and data B shows direct linear relationship. Both data have same magnitude of correlation.

The area under a particular normal curve between 6 and 8 is 0.695. A normally distributed variable has the same mean and standard deviation as the parameters for this normal curve. What percentage of all possible observations of the variable lie between 6 and 8​?

Answers

Answer:

69.5%

Step-by-step explanation:

A feature of the normal distribution is that this is completely determined by its mean and standard deviation, therefore, if two normal curves have the same mean and standard deviation we can be sure that they are the same normal curve. Then, the probability of getting a value of the normally distributed variable between 6 and 8 is 0.695. In practice we can say that if we get a large sample of observations of the variable, then, the percentage of all possible observations of the variable that lie between 6 and 8 is 100(0.695)% = 69.5%.

You have a fair coin. You flip the coin two times. Let T1T1 be the event that the first flip (Flip 1) results in Tails. Let T2T2 be the event that the second flip (Flip 2) results in Tails. Are the events T1T1 and T2T2 independent?

Answers

Answer:

Yes, the events T1 and T2 are independent.

Step-by-step explanation:

When flipping a fair coin, for each flip, there is a 50/50 chance that it will result in heads or tails.

For the first flip, P(T1) = 0.5

For the second flip, P(T2) = 0.5 regardless of the outcome of the first flip. Therefore, T1 and T2 are independent events.

*Note that if the question asked for the event of both flips resulting in tails, then the events would be dependent.

A2 = [1 2 3; 4 5 6; 7 8 9; 3 2 4; 6 5 4; 9 8 7]
b2 = [1 1 1 1 1 1]′

(a) Find a basis for the row space of A2.
(b) How many solutions does A2 ?

Answers

Answer:

Remember, a basis for the row space of a matrix A is the set of rows different of zero of the echelon form of A.

We need to find the echelon form of the matrix augmented matrix of the system A2x=b2

[tex]B=\left[\begin{array}{cccc}1&2&3&1\\4&5&6&1\\7&8&9&1\\3&2&4&1\\6&5&4&1\\9&8&7&1\end{array}\right][/tex]

We apply row operations:

1.

To row 2 we subtract row 1, 4 times.To row 3 we subtract row 1, 7 times.To row 4 we subtract row 1, 3 times.To row 5 we subtract row 1, 6 times.To row 6 we subtract row 1, 9 times.

We obtain the matrix

[tex]\left[\begin{array}{cccc}1&2&3&1\\0&-3&-6&-3\\0&-6&-12&-6\\0&-4&-5&-2\\0&-7&-14&-5\\0&-10&-20&-8\end{array}\right][/tex]

2.

We subtract row two twice to row three of the previous matrix.we subtract 4/3 from row two to row 4.we subtract 7/3 from row two to row 5.we subtract 10/3 from row two to row 6.

We obtain the matrix

[tex]\left[\begin{array}{cccc}1&2&3&1\\0&-3&-6&-3\\0&0&0&0\\0&0&3&2\\0&0&0&2\\0&0&0&2\end{array}\right][/tex]

3.

we exchange rows three and four of the previous matrix and obtain the echelon form of the augmented matrix.

[tex]\left[\begin{array}{cccc}1&2&3&1\\0&-3&-6&-3\\0&0&3&2\\0&0&0&0\\0&0&0&2\\0&0&0&2\end{array}\right][/tex]

Since the only nonzero rows of the augmented matrix of the coefficient matrix are the first three, then the set

[tex]\{\left[\begin{array}{c}1\\2\\3\end{array}\right],\left[\begin{array}{c}0\\-3\\-6\end{array}\right],\left[\begin{array}{c}0\\0\\3\end{array}\right] \}[/tex]

is a basis for Row (A2)

Now, observe that the last two rows of the echelon form of the augmented matrix have the last coordinate different of zero. Then, the system is inconsistent. This means that the system has no solutions.

In a poll of 1000 adults in July​ 2010, 540 of those polled said that schools should ban sugary snacks and soft drinks. Complete parts a and b below. a. Do a majority of adults​ (more than​ 50%) support a ban on sugary snacks and soft​ drinks? Perform a hypothesis test using a significance level of 0.05.State the null and alternative hypotheses. Note that p is defined as the population proportion of people who believe that schools should ban sugary foods.

Answers

Answer:

[tex]z=2.53[/tex]  

[tex]p_v =P(z>2.53)=0.0057[/tex]  

The p value obtained was a very low value and using the significance level given [tex]\alpha=0.05[/tex] we have [tex]p_v<\alpha[/tex] so then we have enough evidence to reject the null hypothesis, and we can say that at 5% of significance, the proportion of adults who support a ban on sugary snacks and soft​ drinks  is more than 0.5 or 50%.

Step-by-step explanation:

1) Data given and notation

n=1000 represent the random sample taken

X=540 represent the adults that said that schools should ban sugary snacks and soft drinks

[tex]\hat p=\frac{540}{1000}=0.54[/tex] estimated proportion of adults that said that schools should ban sugary snacks and soft drinks

[tex]p_o=0.5[/tex] is the value that we want to test

[tex]\alpha=0.05[/tex] represent the significance level

Confidence=95% or 0.95

z would represent the statistic (variable of interest)

[tex]p_v[/tex] represent the p value (variable of interest)  

2) Concepts and formulas to use  

We need to conduct a hypothesis in order to test the claim that majority of adults​ (more than​ 50%) support a ban on sugary snacks and soft​ drinks, the system of hypothesis are:  

Null hypothesis:[tex]p\leq 0.5[/tex]  

Alternative hypothesis:[tex]p > 0.5[/tex]  

When we conduct a proportion test we need to use the z statistic, and the is given by:  

[tex]z=\frac{\hat p -p_o}{\sqrt{\frac{p_o (1-p_o)}{n}}}[/tex] (1)  

The One-Sample Proportion Test is used to assess whether a population proportion [tex]\hat p[/tex] is significantly different from a hypothesized value [tex]p_o[/tex].

3) Calculate the statistic  

Since we have all the info requires we can replace in formula (1) like this:  

[tex]z=\frac{0.54 -0.5}{\sqrt{\frac{0.5(1-0.5)}{1000}}}=2.53[/tex]  

4) Statistical decision  

It's important to refresh the p value method or p value approach . "This method is about determining "likely" or "unlikely" by determining the probability assuming the null hypothesis were true of observing a more extreme test statistic in the direction of the alternative hypothesis than the one observed". Or in other words is just a method to have an statistical decision to fail to reject or reject the null hypothesis.  

The significance level provided [tex]\alpha=0.05[/tex]. The next step would be calculate the p value for this test.  

Since is a one side right tailed test the p value would be:  

[tex]p_v =P(z>2.53)=0.0057[/tex]  

So the p value obtained was a very low value and using the significance level given [tex]\alpha=0.05[/tex] we have [tex]p_v<\alpha[/tex] so then we have enough evidence to reject the null hypothesis, and we can say that at 5% of significance, the proportion of adults who support a ban on sugary snacks and soft​ drinks  is more than 0.5 or 50%.

Willow Brook National Bank operates a drive-up teller window that allows customers to complete bank transactions without getting out of their cars. On weekday mornings, arrivals to the drive-up teller window occur at random, with an arrival rate of 24 customers per hour or 0.4 customers per minute.
(a) What is the mean or expected number of customers that will arrive in a five-minute period?
(b) Use the arrival rate in part (a) and compute the probabilities that exactly 0, 1, 2, and 3 customers will arrive during a five-minute period. If required, round your answers to four decimal places.
(c) Delays are expected if more than three customers arrive during any five-minute period. What is the probability that delays will occur? If required, round your answer to four decimal places.

Answers

Answer:

2, 0.135, 0.270, 0.270, 0.180, 0.145

Step-by-step explanation:

1. To calculate the mean of people arriving in 5 minute period:

We know the arrival rate of minute is 0.4, so people arriving in 5 minutes will be

0.4 x 5 = 2

2. From part 1 it is known thay mean arrival time=2

For this we will use poisson's probability formula that is

P(X=x) = (2^x) x Exp^(-2/x!)

For X=0

P(X=0) = (2^0) x Exp^(-2/0!) = 0.135

For X = 1

P(X=1) = (2^1) x Exp^(-2/1!) = 0.270

For X = 2

P(X=2) = (2^2) x Exp^(-2/2!) = 0.270

For X = 3

P(X=3) = (2^3) x Exp^(-2/3!) = 0.180

3. For delay expected if more than 3 customer arrive in 5 minutes.

P(X>3) = 1 - P(X=0) - P(X=1) - P(X=2) - P(X=3)

P(X>3) = 1-0.135-0.270-0.270-0.180

P(X>3) = 0.145

The average life a manufacturer's blender is 5 years, with a standard deviation of 1 year. Assuming that the lives of these blenders follow approximately a normal distribution, find the probability that the mean life a random sample of 25 such blenders falls between 4.6 and 5.1 years.

Answers

Answer:

The probability that the mean life a random sample of 25 such blenders falls between 4.6 and 5.1 years is 0.6687.

Step-by-step explanation:

We have given :

The average life a manufacturer's blender is 5 years i.e. [tex]\mu=5[/tex]

The standard deviation is [tex]\sigma=1[/tex]

Number of sample n=25.

To find : The probability that the mean life falls between 4.6 and 5.1 years ?

Solution :

Using z-score formula, [tex]z=\frac{x-\mu}{\frac{\sigma}{\sqrt{n}}}[/tex]

The probability that the mean life falls between 4.6 and 5.1 years is given by, [tex]P(4.6<X<5.1)[/tex]

[tex]P(4.6<X<5.1)=P(\frac{4.6-5}{\frac{1}{\sqrt{25}}}<Z<\frac{5.1-5}{\frac{1}{\sqrt{25}}})[/tex]

[tex]P(4.6<X<5.1)=P(\frac{-0.4}{\frac{1}{5}}<Z<\frac{0.1}{\frac{1}{5}})[/tex]

[tex]P(4.6<X<5.1)=P(-2<Z<0.5)[/tex]

[tex]P(4.6<X<5.1)=P(Z<0.5)-P(Z<-2)[/tex]

Using z-table,

[tex]P(4.6<X<5.1)=0.6915-0.0228[/tex]

[tex]P(4.6<X<5.1)=0.6687[/tex]

Therefore, the probability that the mean life a random sample of 25 such blenders falls between 4.6 and 5.1 years is 0.6687.

Final answer:

The probability that the mean life of a random sample of 25 blenders falls between 4.6 and 5.1 years is approximately 0.3585, or 35.85%.

Explanation:

To find the probability that the mean life of a random sample of 25 blenders falls between 4.6 and 5.1 years, we can use the standard normal distribution. First, we need to standardize the values using the z-score formula. The z-score for 4.6 years is (4.6 - 5) / 1 = -0.4, and the z-score for 5.1 years is (5.1 - 5) / 1 = 0.1. We can then look up the corresponding probabilities in the standard normal distribution table or use a calculator to find the area under the curve between these two z-scores. The probability that the mean life falls in this range is approximately 0.3585, or 35.85%.

Learn more about Probability here:

https://brainly.com/question/32117953

#SPJ11

A typist makes an average of 5 typo errors per page that she types. If the number of errors per each typed page can be modeled according to the Poisson distribution, what is the probability that she will make more than 3 typo errors in the next page? Express your answer in decimals and round to two significant places after the decimal. For example 0.1678 should be entered as 0.17.

Answers

Answer:

Step-by-step explanation:

what are the next two terms in the sequence -16, 4, -1, 1/4

Answers

Answer: fifth term = -1/16

Sixth term = 1/256

Step-by-step explanation:

The given sequence is a geometric progression. This is because the ratio of two consecutive terms is constant.

We will apply the formula for determining the nth term of a geometric progression series.

Tn = ar^n-1

Where

Tn = value of the nth term of the geometric series

a = The first term of the series.

r = common ratio(ratio of a term to a consecutive previous term)

n = number of terms in the series

From the in information given,

a = -16

r = 4/-16 = -1/4

The next 2 terms are the 5th and 6th terms.

T5 = -16 × -1/4^(5-1)

T5 = -16 × (-1/4)^4

T5 = -16 × 1/256 = -1/16

The 6th term would be the 5th term × the common ratio. It becomes

T6 = -1/16 ×-1/4 = 1/256

A fair coin is tossed three times and the events A, B, and C are defined as follows: A:{ At least one head is observed } B:{ At least two heads are observed } C:{ The number of heads observed is odd } Find the following probabilities by summing the probabilities of the appropriate sample points (note that 0 is an even number):
(a) P(B) =
(b) P(A or B) =
(c) P(A or B or C)

Answers

Answer:

(a) 1/2

(b) 1/2

(c) 1/8

Step-by-step explanation:

Since, when a fair coin is tossed three times,

The the total number of possible outcomes

n(S) = 2 × 2 × 2

= 8 { HHH, HHT, HTH, THH, HTT, THT, TTH, TTT },

Here, B : { At least two heads are observed } ,

⇒ B = {HHH, HHT, HTH, THH},

⇒ n(B) = 4,

Since,

[tex]\text{Probability}=\frac{\text{Favourable outcomes}}{\text{Total outcomes}}[/tex]

(a) So, the probability of B,

[tex]P(B) =\frac{n(B)}{n(S)}=\frac{4}{8}=\frac{1}{2}[/tex]

(b) A : { At least one head is observed },

⇒ A = {HHH, HHT, HTH, THH, HTT, THT, TTH},

∵ A ∩ B = {HHH, HHT, HTH, THH},

n(A∩ B) = 4,

[tex]\implies P(A\cap B) = \frac{n(A\cap B)}{n(S)} = \frac{4}{8}=\frac{1}{2}[/tex]

(c) C: { The number of heads observed is odd },

⇒ C = { HHH, HTT, THT, TTH},

∵ A ∩ B ∩ C = {HHH},

⇒ n(A ∩ B ∩ C) = 1,

[tex]\implies P(A\cap B\cap C)=\frac{1}{8}[/tex]

Other Questions
how can a person's genotype for a trait be determined from his or her phenotype for the trait? You have to see if the sentences are singular or plural nounsThe family (is,are) going on vacation to GeorgiaThe school staff worked throughout the summer on (its, their) lesson planThat group of spectators (is,are) getting awfully rowdyThe set of books fell from their shelfThe audience (is,are) returning to (its, their) carsThe staff (was, were) very happy about (its, their) bonuses Find three consecutive odd integers such that the sum of the first is two less than the second,and three more than the third is 70 99 POINTS!Find the standard deviation for the binomial distribution.n=21; p=0.2A) 1.83B) 5.95C) -0.58D) 5.10 Suppose that two populations have the same mean. A researcher draws a sample of size 35 from each population and calculates the difference in sample means. He then repeats this process 99 more times, resulting in 100 calculated differences in sample means. The researcher finds the standard error of the difference in sample means to be 1.78. Which of the following statements is true regarding the distribution of the differences in sample means? The center of the distribution will be approximately 0, with about 68 percent of the differences in means between -3.56 and 3.56 Raycom Construction needs heavy-duty equipment to install a new pipeline in northern Alaska. Raycom's engineers have been asked to provide detailed specifications and recommendations for the equipment needed. The Raycom engineers will primarily play the __________ role in the company's buying center.a. userb. initiatorc. gatekeeperd. buyere. influencer While you were visiting a friend, someone robbed their apartment and stole your laptop computer. Unfortunately, they did not have renter's insurance. Where can you look for help to replace your computer You expect a share of stock to pay dividends of $1.00, $1.25, and $1.50 in each of the three years. You believe the stock will sell for $20 at the end of the third year. What is the stock price if the discount rate for the stock is 10%? When using the direct write-off method off accounting for uncollectible receivables, the account Allowance for Doubtful Accounts is debited when a specific account is determined to be uncollectible. True or False Water is boiling in an aluminum pan placed on an electrical element on a stovetop. The pan has a bottom that is 0.800 cm thick and 14.0 cm in diameter. Aluminum thermal conductivity is 220 W/(m oC). In every second, 1.2 g boiling water evaporates. The latent heat of vaporization for water is 2.26 106 J/kg. (a) How much heat is transfered to the boiling water in one second? A woman heterozygous for A blood marries a man heterozygous for B blood. What is the probability that they will produce offspring with AB blood? a)0%b)25%c)50%d)75% Which of the following is a true statement? Mucus protects the stomach lining from digestive secretions. Protease breaks down lipids into fatty acids and glycerol. Lipase breaks down proteins in the small intestine. Pepsin is an antibacterial agent that kills some bacteria. Ill put you as brainliest Architects often create scale models before the actual building is constructed. If a scale model has a length of 24 inches and a width of 36 inches, which dimensions are geometrically similar to the model building ?Building A: 223 feet by 360 feet Building C: 288 feet by 432 feet Building D: 364 feet by 576 feet Building B: 120 feet by 190 feet Wilson Co. purchased land as a factory site for $1,350,000. Wilson paid $120,000 to tear down two buildings on the land. Salvage was sold for $8,100. Legal fees of $5,220 were paid for title investigation and making the purchase. Architect's fees were $46,800. Title insurance cost $3,600, and liability insurance during construction cost $3,900. Excavation cost $15,660. The contractor was paid $4,200,000. An assessment made by the city for pavement was $9,600. Interest costs during construction were $255,000.The cost of the land that should be recorded by Wilson Co. is? Which issue is related to long-term heroin use? What is an example of nuance? Two kids create a makeshift seesaw by setting a 4-m long uniform plank on a saw horse. The saw horse is 0.5 m to the left of the center of mass of the plank. The child of mass m1 = 42 kg sits at the left end of the plank. The child of mass m2 = 31 kg sits 1 m to the right of the center of mass of the plank. What is the mass of the plank? If 15 people eats a quarter pound of turkey how much turkey is needed to feed everyone Graph the line with the y intercept 8 and slope -6 Matt has a 5lb bag of apples to make a pie he needs to use 3/5 of the bad how many pounds of apples we use for the pie explain what a model for this problem might look like