(1 point) A computer retail store has 8 personal computers in stock. A buyer wants to purchase 4 of them. Unknown to either the retail store or the buyer, 4 of the computers in stock have defective hard drives. Assume that the computers are selected at random. (a) In how many different ways can the 4 computers be chosen

Answer:

16.1 my friend

Step-by-step explanation:

Answer:

16.1

Step-by-step explanation:

Remember to always follow PEMDAS. In this case, we need to multiply before we divide.

10 x .89 + 7.2

8.9 + 7.2 = 16.1

The answer is 16.1

Final answer:

The height of the tree is approximately 113.85 feet, which is determined by using the tangent of the given angle of elevation (68°) and the distance from the tree (46 feet) in a trigonometric calculation.

Explanation:

To find the height of the tree, we can use trigonometry. The student is 46 feet from the tree, and the angle of elevation to the top of the tree is 68°. The height of the tree can be found using the tangent function in a right triangle, where the opposite side is the tree height (h), and the adjacent side is the distance from the tree (46 feet). The tangent of the angle of elevation (θ) is the ratio of the opposite side to the adjacent side.

So, tan(68°) = h / 46 feet. To find the height (h), multiply both sides by 46 feet:

h = 46 feet × tan(68°)

We can use a calculator to find that tan(68°) is approximately 2.475. Now, multiply 46 feet by this tangent value to get the height:

h = 46 feet × 2.475h = 113.85 feet (rounded to two decimal places)

Therefore, the height of the tree is approximately 113.85 feet.

Answer:

a) [tex]\delta = 1.4\,\%[/tex], b) [tex]\delta_{max} = 1.35\,\%[/tex]

Step-by-step explanation:

a) The area formula for a square is:

[tex]A =l^{2}[/tex]

The total differential for the area is:

[tex]\Delta A = \frac{\partial A}{\partial l}\cdot \Delta l[/tex]

[tex]\Delta A = 2\cdot l \cdot \Delta l[/tex]

The absolute error for the area of the square is:

[tex]\Delta A = 2\cdot (10\,cm)\cdot (0.07\,cm)[/tex]

[tex]\Delta A = 1.4\,cm^{2}[/tex]

Thus, the relative error is:

[tex]\delta = \frac{\Delta A}{A}\times 100\,\%[/tex]

[tex]\delta = \frac{1.4\,cm^{2}}{100\,cm^{2}} \times 100\,\%[/tex]

[tex]\delta = 1.4\,\%[/tex]

b) The maximum allowable absolute error for the area of the square is:

[tex]\Delta A_{max} = \left(\frac{\delta}{100} \right)\cdot A[/tex]

[tex]\Delta A_{max} = \left(\frac{2.7}{100} \right)\cdot (100\,cm^{2})[/tex]

[tex]\Delta A_{max} = 2.7\,cm^{2}[/tex]

The maximum allowable absolute error for the length of a side of the square is:

[tex]\Delta l_{max}= \frac{\Delta A_{max}}{2\cdot l}[/tex]

[tex]\Delta l_{max} = \frac{2.7\,cm^{2}}{2\cdot (10\,cm)}[/tex]

[tex]\Delta l_{max} = 0.135\,cm[/tex]

Lastly, the maximum allowable relative error is:

[tex]\delta_{max} = \frac{\Delta l_{max}}{l}\times 100\,\%[/tex]

[tex]\delta_{max} = \frac{0.135\,cm}{10\,cm} \times 100\,\%[/tex]

[tex]\delta_{max} = 1.35\,\%[/tex]

Answer:

–11 and 2

Step-by-step explanation:

observe

x² + 9x – 22 = 0

(x + 11)(x – 2) = 0

x = –11 or x = 2

Answer:

Hence total of 10 students are not able to complete the exam.

Step-by-step explanation:

Given:

Mean for completing exam =80 min

standard deviation =10 min.

To find:

how much student will not complete the  exam?

Solution:

using the Z-table score we can calculate the required probability.

Z=(Required time -mean)/standard deviation.

A standard on an avg class contains:

60 students.

consider for 70 mins and then 90 mins (generally calculate ±  standard deviation of mean)(80-10 and 80+10).

1)70 min

Z=(70-80)/10

Z=-1

Now corresponding p will be

P(z=-1)

=0.1587

therefore

Now for required 90 min will be

Z=(90-80)/10

=10/10

z=1

So corresponding value of p is

P(z<1)=0.8413

this means 0.8413 of 60 students are able to complete the exam.

0.8413*60

=50.47

which approximate 50 students,

total number =60

and total number student will able to complete =50

Total number of student will not complete =60-50

=10.

About 15.87% of college students are expected not to finish the final examination within the 90-minute time limit, based on the properties of the normal distribution with a mean of 80 minutes and a standard deviation of 10 minutes.

The student's question involves using the properties of the normal distribution to determine the percentage of students who will not finish a final examination in the given time frame.

To compute this, we need to calculate the z-score that corresponds to the 90-minute time limit. The z-score formula is:

Z = (X - μ) / σ

where X is the value of interest, μ (mu) is the mean, and σ (sigma) is the standard deviation. Plugging in the numbers:

Z = (90 - 80) / 10 = 1

A z-score of 1 corresponds to a percentile of approximately 84.13%, meaning about 84.13% of students will finish within 90 minutes. To find the percentage that will not finish in time, we subtract this from 100%:

100% - 84.13% = 15.87%

Therefore, approximately 15.87% of the class will not finish the exam in time.

Answer:

  Its magnitude will be larger than 0.004.

Step-by-step explanation:

When a divisor is less than 1, the quotient will be greater than the dividend.

When the divisor is "almost zero", the quotient will be much greater than the dividend. Here, the dividend may be considered to be "almost zero", so we cannot say anything about the actual quotient except to say its magnitude will be greater than the dividend.

_____

The dividend is positive, so the quotient will have the same sign as the divisor. (Negative divisors can be "almost zero," too.)

Answer:A+b

by-step explanation:

Answer:

you have the correct answer!

Step-by-step explanation:

Answer:

Step-by-step explanatio n: ummmoirnd iehcn

Answer:

We can be 95% sure that the true population mean zinc concentration is between 8.8 mg/g and 9.5 mg/g.

Step-by-step explanation:

Given that

N = Sample = 56

Confidence Interval = 95%

Mean Interval = 8.8 mg/g to 9.5 mg/g

UB = Upper Bound = 9.5mg/g

LB = Lower Bound = 8.8mg/g

The sample mean was 9.15mg/g

The sample mean is gotten from ½(UB + LB)

Sample Mean = ½(8.8 + 9.5)

Sample Mean = ½ * 18.3

Sample Mean = 9.15mg/g

From the definition of confidence Interval;

"Confidence Interval is a range of values so defined that there is a specified probability that the value of a parameter lies within it"

This means that the best interpretation of the data given is "the mean value of the 56 sample of fishes is between 8.8mg/g and 9.5mg/g;"

With 8.8mg/g as the lower bound and 9.9mg/g as the upper bound.

Answer:

[tex]x + 1[/tex]

Step-by-step explanation:

log(x) is the inverse function of an exponent. "log base 8 of xyz" means "what number do I have to raise 8 to, to get xyz". In this case, it means, "what number do I have to raise 8 to, to get x + 1". That's simple, it's just x + 1!

Answer:

a) [tex] P(-1<Z<1)= P(Z<1) -P(Z<-1)= 0.841-0.159= 0.682[/tex]

b) [tex] P(-2<Z<2)= P(Z<2) -P(Z<-2)= 0.977-0.0228= 0.954[/tex]

c) [tex] P(-3<Z<3)= P(Z<3) -P(Z<-3)= 0.999-0.0013= 0.998[/tex]

The results are on the fogure attached.

Step-by-step explanation:

Previous concepts

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".  

Solution to the problem

Part a

For this case we want to find this probability:

[tex] P(-1<Z<1)[/tex]

And we can find this probability with this difference:

[tex] P(-1<Z<1)= P(Z<1) -P(Z<-1)[/tex]

And if we find the probability using the normal standard distribution or excel we got:

[tex] P(-1<Z<1)= P(Z<1) -P(Z<-1)= 0.841-0.159= 0.682[/tex]

Part b

For this case we want to find this probability:

[tex] P(-2<Z<2)[/tex]

And we can find this probability with this difference:

[tex] P(-2<Z<2)= P(Z<2) -P(Z<-2)[/tex]

And if we find the probability using the normal standard distribution or excel we got:

[tex] P(-2<Z<2)= P(Z<2) -P(Z<-2)= 0.977-0.0228= 0.954[/tex]

Part c

For this case we want to find this probability:

[tex] P(-3<Z<3)[/tex]

And we can find this probability with this difference:

[tex] P(-3<Z<3)= P(Z<3) -P(Z<-3)[/tex]

And if we find the probability using the normal standard distribution or excel we got:

[tex] P(-3<Z<3)= P(Z<3) -P(Z<-3)= 0.999-0.0013= 0.998[/tex]

Final answer:

The question asks to find the area under the standard normal curve for specific z-score ranges. Using the empirical rule, we conclude that respective areas for those ranges are approximately 68%, 95%, and 99.7%. The exact areas can be found using a Z-table.

Explanation:

The question involves finding the area under the standard normal curve between specified z-scores. This is a fundamental concept in statistics, often used to find probabilities related to normally distributed data.

To find the exact areas based on the z-scores, we can refer to the Z-table of Standard Normal Distribution. This table lists the cumulative probabilities from the mean up to a certain z-score. By looking up the area to the left of each positive z-score and doubling it, we can get the approximate area between the negative and positive z-scores mentioned above.

Answer:

Equation:  [tex]F=1500(1.0025)^{12t}[/tex]

The balance after 5 years is:  $1742.43

Step-by-step explanation:

This is a compound growth problem . THe formula is:

[tex]F=P(1+\frac{r}{n})^{nt}[/tex]

Where

F is future amount

P is present amount

r is rate of interest, annually

n is the number of compounding per year

t is the time in years

Given:

P = 1500

r = 0.03

n = 12 (compounded monthly means 12 times a year)

The compound interest formula modelled by the variables is:

[tex]F=1500(1+\frac{0.03}{12})^{12t}\\F=1500(1.0025)^{12t}[/tex]

Now, we want balance after 5 years, so t = 5, substituting, we get:

[tex]F=1500(1.0025)^{12t}\\F=1500(1.0025)^{12*5}\\F=1500(1.0025)^{60}\\F=1742.43[/tex]

The balance after 5 years is:  $1742.43

Answer:

Explanation:

The amount of animal waste one zoo is diposing daily is approximately normal with:

The proportion of waste over 350 lbs may be found using the table for the area under the curve for the cumulative normal standard probability.

First, find the z-score for 350 lbs:

      [tex]z-score=\dfrac{X-\mu}{\sigma}[/tex]

      [tex]z-score=\dfrac{350lbs-348.5lbs}{38.2lbs}\approx0.04[/tex]

There are tables for the cumulative areas (probabilities) to the left and for the cumulative areas to the right of the z-score.

You want the proportion of the days when the z-score is more than 0.04; then, you can use the table for the values to the rigth of z = 0.04.

From such table, the area or probability is 0.4840.

The attached image shows a portion of the table with that value: it is the cell highlighted in yellow.

Hence, the answer is the option (A) 0.484.

By calculating the z-score for 350 pounds of waste and consulting the standard normal distribution, the proportion of days the zoo can expect to have enough animal waste to power the entire aquarium is approximately 0.484.

To determine the proportion of days the zoo can expect to generate enough animal waste to run the entire aquarium, we can use z-scores in a normal distribution. Given the mean (μ = 348.5) and standard deviation (σ = 38.2), we want to find the proportion of the data that is above 350 pounds.

First, we calculate the z-score for 350 pounds:

z = (X - μ) / σ = (350 - 348.5) / 38.2 ≈ 0.04

Now we need to find the probability that the z-score is greater than 0.04. Consulting a standard normal distribution table or using a calculator, this gives us a probability of approximately 0.484.

Therefore, the proportion of the days the zoo can expect to obtain enough waste to cover the energy demands for the entire aquarium is 0.484.

Answer:

A. [tex]\sqrt{64}=8[/tex] miles

Step-by-step explanation:

Given two Cartesian coordinates [tex](x_1,y_1)\&(x_2,y_2)[/tex], the distance between the points is given as:

[tex]d = \sqrt{((x_1-x_2)^2+(y_1-y_2)^2)}[/tex]

Converting to polar coordinates

[tex](x_1,y_1) = (r_1 cos \theta_1, r_1 sin \theta_1)\\(x_2,y_2) = (r_2 cos \theta_2, r_2 sin \theta_2)[/tex]

Substitution into the distance formula gives:

[tex]\sqrt{((r_1 cos\theta_1-r_2 cos \theta_2)^2+(r_1 sin \theta_1-r_2 sin \theta_2)^2}\\=\sqrt{(r_1^2+r_2^2-2r_1r_2(cos \theta_1 cos \theta_2+sin\theta_1 sin \theta_2) }\\= \sqrt{r_1^2+r_2^2-2r_1r_2cos (\theta_1 -\theta_2)}[/tex]

In the given problem,

[tex](r_1,\theta_1)=(8 mi, 63^0) \:and\: (r_2,\theta_2)=(8 mi, 123^0 ).[/tex]

[tex]Distance=\sqrt{8^2+8^2-2(8)(8)cos (63 -123)}\\=\sqrt{128-128cos (-60)}\\=\sqrt{64}=8 mile[/tex]

The closest option is  A. [tex]\sqrt{64}=8[/tex] miles

Answer:

Step-by-step explanation:

quadratic equation: ax² + bx + c =0

x' = [-b+√(b²-4ac)]/2a   and x" =  [-b-√(b²-4ac)]/2a  

6 = x² – 10x ; x² - 10x -6 =0

(a=1, b= - 10 and c = - 6

x' = [10+√(10²+4(1)(-6)]/2(1)  and x" = [10-√(10²+4(1)(-6)]/2(1)

x' =5+√31  and x' = 5-√31

Answer:

To check that V is a vector space it suffice to show

1. Associativity of vector addition.

2. Additive identity

3. Existence of additive identity

4. Associativity of scalar multiplication

5. Distributivity of scalar sums

6.  Distributivity of vector sums

7. Existence of scalar multiplication identity.

Step-by-step explanation:

To see that V is a vector space we have to see that.

1. Associativity of vector addition.

This property is inherited from associativity of the sum on the real numbers.

2. Additive identity.

The additive identity in this case, would be the null function f(x)=0 . for every real x.   It is inherited from the real numbers that the null function will be the additive identity.

3. Existence of additive inverse for any function f(x).

For any function f(x), the function -f(x) will be the additive inverse. It is in inherited from the real numbers that f(x)-f(x) = 0.

4. Associativity of scalar multiplication.

Associativity of scalar multiplication  is inherited from associativity of the real numbers

5. Distributivity of scalar sums:

Given any two scalars r,s and a function f, it will be inherited from the distributivity of the real numbers that

(r+s)f(x) = rf(x) + sf(x)

Therefore, distributivity of scalar sums is valid.

5. Distributivity of vector sums:

Given scalars r  and two functions f,g, it will be inherited from the distributivity of the real numbers that

r (f(x)+g(x)) = r f(x) + r g(x)

Therefore, distributivity of vector sums is valid.

6. Scalar multiplication identity.

The scalar 1 is the scalar multiplication identity.

.24 is equivalent to

24%

24/100

6/25

12/50, and more!

Hope this helped

Answer:

A. $1500

Step-by-step explanation:

We need to find the countertop area, so let's calculate the areas of the rectangles that the problem broke the countertop into:

1. "1 rectangle has a base of 70 inches and height of 20 inches"

The area of a rectangle is denoted by: A = bh, where b is the base and h is the height. Here, b = 70 and h = 20, so the area is: A = 70 * 20 = 1400 inches squared

2. "The other rectangle has a base of 20 inches and height of 30 inches"

Again, use A = bh: b = 20 and h = 30, so A = 20 * 30 = 600 inches squared

Add up these two areas: 1400 + 600 = 2000 inches squared.

The problem says that the cost is $0.75 per square inch, so multiply this by 2000 to get the total cost of 2000 square inches:

2000 * 0.75 = $1500

Thus, the answer is A.

Hope this helps!

Answer:

$1500

Step-by-step explanation:

You can divide this figure into 2 rectangle with dimensions:

1) 70 × 20

2) 20 × (50-20: 20 × 30

Area:

(70×20) + (20×30)

1400 + 600

2000 in²

Cost per in²: 0.75

2000in² cost:

2000 × 0.75

$1500

Answer:

.5

Step-by-step explanation:

-1.9+4=2.1

2.1+(-1.6)=.5

Answer:

Step-by-step explanation:

This is permutation question

The formula for it:

Finding the answer:

The Taylor polynomial approximation to f(x) = 1/x up to degree 2 about x=a was calculated. It was mentioned that Taylor's inequality could be used to estimate the accuracy of this approximation. However, due to the lack of necessary information, an exact error bound or graphical check couldn't be determined.

To begin the solution, we'll need to find the first couple of derivatives for the function f(x) = 1/x. The first derivative is f'(x) = -1/x² and the second derivative is f''(x) = 2/x³. These derivatives will be used to form the Taylor series approximation.

The Taylor series polynomial of degree 2 is given by the formula T₂(x) = f(a) + f'(a)*(x-a) + f''(a)*(x-a)²/2!, where a is the point we are approximating about and n is the degree of the Taylor polynomial. Substituting the given values, we get: T₂(x) = 1/1 - 1/1² * (x-1) + 2/1³ * (x-1)²/2!.

To estimate the accuracy of this approximation, we use Taylor's Inequality which provides an upper bound for the absolute error. The remainder term in Taylor's series is given by |R₂(x)| ≤ M * |x - a|³ / (3!*n), where M is the maximum value of the absolute third derivative on the interval [a, x]. After applying Taylor's inequality, we can get an accuracy estimate but unfortunately, the information provided doesn't give enough specifics for an exact calculation.

Finally, to verify the result graphically, you would plot |R₂(x)|, but without the explicit remainder term, this cannot be done.

https://brainly.com/question/34375801

#SPJ12

Answer:

A certain company makes 12-volt car batteries. After many years of product testing, the company knows that the average life of a battery is normally distributed, with a mean of 50 months and a standard deviation of 9 months. If the company does not want to make refunds for more than 10% of its batteries under the full-refund guarantee policy, for how long should the company guarantee the batteries?

The company should guarantee the batteries for 38 months.

Step-by-step explanation:

Using standard normal table,

P(Z < z) = 10%

=(Z < z) = 0.10

= P(Z <- 1.28 ) = 0.10

z = -1.28

Using z-score formula  

x = zσ  + μ

x = -1.28 *9+50

x = 38

Therefore, the company should guarantee the batteries for 38 months.

Answer:

The company should guarantee the batteries (to the nearest month) for 38 months.

Step-by-step explanation:

We have here a normally distributed data. The random variable is the average life of the batteries.

From question, we can say that this random variable has a population mean of 50 months and population standard deviation of 9 months. We can express this mathematically as follows:

[tex] \\ \mu = 50[/tex] months.

[tex] \\ \sigma = 9[/tex] months.

The distribution of the random variable (the average life of the batteries) is the normal distribution, and it is determined by two parameters, namely, the mean [tex] \\ \mu[/tex] and [tex] \\ \sigma[/tex], as we already know.

For the statement: "The company does not want to make refunds for more than 10% of its batteries under the full-refund guarantee policy", we can say that it means that we have determine, first, how many months last less of 10% of the batteries that its average life follows a normal distribution or are normally distributed?

To find this probability, we can use the standard normal distribution, which has some advantages: one of the most important is that we can obtain the probability of any normally distributed data using standardized values given by a z-score, since this distribution (the normal standard) has a mean that equals 0 and standard distribution of 1.

Well, the z-score is given by the formula:

[tex] \\ z = \frac{x - \mu}{\sigma}[/tex] [1]

Where, x is a raw score coming from a normally distributed data. This is the value that we have to transform into a z-score, that is, in a standardized value.

However, from the question, we want to know what value of z represents a cumulative probability of 10% in the cumulative standard normal distribution. We can find it using the standard normal table, available in Statistics books or on the Internet (of course, we can use also Statistics packages or even spreadsheets to find it).

Then, the value of z is, approximately, -1.28, using a cumulative standard normal table for negative values for z. If the cumulative standard normal only has positive values for z, we can obtain it, using the following:

[tex] \\ P(z<-a) = 1 - P(z<a) =P(z>a)[/tex]

That is, P(z<-1.28) = P(z>1.28). The probability for P(z<1.28) is approximately, 90%.

Therefore, using the formula [1]:

[tex] \\ z = \frac{x - \mu}{\sigma}[/tex]

[tex] \\ -1.28 = \frac{x - 50}{9}[/tex]

 [tex] \\ -1.28 * 9 = x - 50[/tex]

 [tex] \\ -11.52 = x - 50[/tex]

[tex] \\ -11.52 + 50 = x[/tex]

[tex] \\ 38.48 = x[/tex]

[tex] \\ x = 38.48[/tex] months.

That is, less than 10% of the batteries have a average life of 38.48 months. Thus, the company should guarantee the batteries (to the nearest month) for 38 months.

Answer:

The prorated monthly cost for tuition and fees and textbooks is ​$707

Step-by-step explanation:

Each semester costs $4000 + $240 = $4240.

A year has 12 months. A semester is 6 months. 12/6 = 2. So an year has two semesters.

The yearly cost is 2*$4240 = $8480

Monthly cost

12 months cost $8480

$8480/12 = $706.67

So the answer is:

Rounded to the nearest dollar

The prorated monthly cost for tuition and fees and textbooks is ​$707

The prorated monthly cost for tuition and fees and textbooks is $707

Total cost per semester = Fees for each semester + Cost of textbook per semester

= $4000 + $240

= $4,240

= 2 × $4,240

= $8480

= $8480 / 12

= $706.666666666666

Approximately,

$707

Learn more about equation:

https://brainly.com/question/11408596

Step-by-step explanation:

Bringing like terms on one side

2 + 7 - 5 = 2x - 4x

9 - 5 = - 2x

4 = - 2x

4/ - 2 = x

- 2 = x

Answer:

z = 1.83<1.96

null hypothesis is accepted

The sample is came from a population mean

Step-by-step explanation:

Step :-1

The sample of 40 measured voltage amounts from a unit have a mean of 123.59 volts and a standard deviation of 0.31 volts

given sample size n =40

mean of the sample ×⁻ = 123.59 volts

standard deviation of sample σ = 0.31 volts

Step2:-

Null hypothesis :-

the sample is from a population with a mean equal to 120 volts.

H₀ : μ =120

Alternative hypothesis:-

H₁ : μ ≠120

level of significance:- α =0.05

Step 3:-

The test statistic

[tex]z = \frac{x_{-}-mean }{\frac{S.D}{\sqrt{n} } }[/tex]

substitute values and simplification

[tex]z = \frac{123.59-120}{\frac{0.31}{\sqrt{40} } }[/tex]

on simplification we get the calculated value

z = 1.83

The tabulated value z =1.96 at 0.05 % level of significance

Conclusion:-

Calculated Z < The tabulated value z =1.96 at 0.05 % level of significance

so the null hypothesis is accepted

The sample is came from a population mean

Answer: REJECT the null hypothesis; there IS sufficient evidence to warrant a rejection of the claim that the mean voltage is 120 volts.

t-calculated = 73.242

t-critical = 2.023

Answer:

B - -5 < y < 5

Step-by-step explanation:

Range is highest and lowest y value the graph goes to.

You can see on the graph that it does not pass 5 and -5