A multiple choice test is composed of 10 questions. Each question has four possible answers, only one of the four possible answers is correct. A student randomly selects the answer for each question. Assume that all selections are independent. Let X count the student’s number of correct answers on the test. a) What is the expected number of correct answers? Round your answer to the nearest tenth.

Answers

Answer 1

Answer:

Let X the random variable of interest "Number of correct anwers on the tet", on this case we now that:

[tex]X \sim Binom(n=10, p=0.25)[/tex]

And the expected value is given by:

[tex] E(X) = np =10*0.25 = 2.5[/tex]

Step-by-step explanation:

Previous concepts

A Bernoulli trial is "a random experiment with exactly two possible outcomes, "success" and "failure", in which the probability of success is the same every time the experiment is conducted". And this experiment is a particular case of the binomial experiment.

The binomial distribution is a "DISCRETE probability distribution that summarizes the probability that a value will take one of two independent values under a given set of parameters. The assumptions for the binomial distribution are that there is only one outcome for each trial, each trial has the same probability of success, and each trial is mutually exclusive, or independent of each other".

The probability mass function for the Binomial distribution is given as:  

[tex]P(X)=(nCx)(p)^x (1-p)^{n-x}[/tex]  

Where (nCx) means combinatory and it's given by this formula:  

[tex]nCx=\frac{n!}{(n-x)! x!}[/tex]  

Solution to the problem

Let X the random variable of interest "Number of correct anwers on the tet", on this case we now that:

[tex]X \sim Binom(n=10, p=0.25)[/tex]

And the expected value is given by:

[tex] E(X) = np =10*0.25 = 2.5[/tex]


Related Questions

Graph f(x) and its inverse, f^-1(x) , in the same coordinate grid.

Answers

Answer:

Included in screenshot

plz can any1 help me out on this plz
15 points

Answers

Answer:

7/22

Step-by-step explanation:

Drama or Sports:

85 + 200 - 60

225

330 - 225 = 105

Probability: 105/330

7/22

What type of angles are< 1 and <5?





vertical

supplementary

corresponding

complementary

Answers

Answer:

The type of angles of <1 and <5 are corresponding angles

Step-by-step explanation:

Given the following diagram, find the length of CB.

Answers

CB would be the same length as AD bc they are not only parallel but also the same size

What is the value of x in the equation 8 + 4 = 2 (x minus 1)?
A.5
B.StartFraction 11 Over 2 EndFraction
C.StartFraction 13 Over 2 EndFraction
D.7

Answers

The answer t your question is option c because you have to expand the brackets
12=2x-1
Move negative one to the other side as a positive number
13=2x
Divide both sides by two
13/2 is option c

Answer:

It is actually 7

Step-by-step explanation:

yup :)

9=8n what does n=
Please help

Answers

9 over 8 so 9/8 so just write it out with a 9 on top a line under the 9 and the number 8!

In this diagram, like segment AD is tangent and line segment AC is secant. If AB = 6 and BC = 18, what is the length of line segment AD?

Answers

9514 1404 393

Answer:

  12

Step-by-step explanation:

The applicable relationship here is ...

  AD² = AB·AC

  AD = √(AB·(AB +BC)) = √(6·(6+18)) = √144

  AD = 12

Solve the equation for all real values of x. 3tan^2x=3tanx

Answers

The equation 3tan²x = 3tanx solved for all real values of x is [tex]x = n\pi[/tex] or [tex]x = \dfrac{\pi + 4n\pi}{4}[/tex], where n is an integer

Solving the equation for all real values of x.

From the question, we have the following parameters that can be used in our computation:

3tan²x = 3tanx

This can be expressed as

3tan²x - 3tanx = 0

Factor out 3tanx

3tanx(tanx - 1) = 0

Expand

3tanx = 0 or tanx - 1 = 0

So, we have

tanx = 0 or tanx = 1

Take the arctan of both sides

x = tan⁻¹(0) or x = tan⁻¹(1)

Evaluate the arctan for all real values of x.

[tex]x = n\pi[/tex] or [tex]x = \dfrac{\pi + 4n\pi}{4}[/tex], where n is an integer

Brandon works at a nearby electronics store. He makes a commission of 14% on everything he sells. If he sells a camera for $588.00, how much money does Brandon make in commission?

Answers

Answer: cc

Step-by-step explanation:

Answer:

670.32

Step-by-step explanation

whats the area of a circle if the diameter is 24.26 mm

Answers

Answer:

approximately 462.24

Step-by-step explanation:

The answer will be 462 I think ,
Please mark me as the brainiest

Average rooms cleaned per maid day is determined by a) number of rooms occupied divided by number of 8-hour maid shifts. b) number of rooms occupied divided by total number of housekeepers. c) number of shifts multiplied by the number of rooms. d) number of housekeepers multiplied by average number of rooms occupied.

Answers

Answer:

B

Step-by-step explanation:

    Average rooms cleaned per housekeeper day: The average number of rooms cleaned per housekeeper day is  performance ratio that gives an idea of how many rooms each housekeeper cleaned.

Average rooms cleaned per housekeeper day = [tex]\frac{ Number of rooms occupied}{Number of full-time housekeepers}[/tex]

Solve the inequality.
8+8(x + 4) >32
The solution is

Answers

Answer:

Isolate the variable by dividing each side by factors that don't contain the variable.

Inequality Form:   x > - 1

Step-by-step explanation:

Answer:

x  > -1

Step-by-step explanation:

To solve, we must isolate the variable, x

8+8(x + 4) >32

Distribute the 8

8+ 8*x +8*4

8+8x+ 32 >32

Combine like terms

8+32 +8x  >32

40 + 8x >32

Subtract 40 from both sides

8x  > -8

Divide both sides by 8

x  > -1

What is the length of a rectangle with width 18 in, and area 135 in 2?

Answers

Answer: The length of a rectangle would be 7.5

Step-by-step explanation:

To find the length is [tex]l = \frac{A}{w}[/tex]

-Solve:

[tex]l=\frac{135}{18}[/tex]

-Divide 135 by 18 and you get 7.5

[tex]\frac{135}{18} = 7.5[/tex]

-Result:

[tex]l= 7.5[/tex]

Luisa Díaz drove her vehicle about 7,200 miles last year. Her fixed costs totaled $1,058.40 and her variable costs were $1965.60 how much did it cost per mile

Answers

Answer:

$0.42

Step-by-step explanation:

Given:

Luisa Díaz drove her vehicle about 7,200 miles last year.

Total fixed cost = $1,058.40

Total variable cost = $1965.60

Question asked:

How much did it cost per mile ?

Solution:

Total cost of driving 7200 miles = Total fixed cost + Total variable cost

                                                     = $1,058.40 + $1965.60

                                                     = $3024

By unitary method:

Cost of driving 7200 miles = $3024

Cost of driving 1 mile = $3024 [tex]\div[/tex] 7200

                                   = $0.42

Thus, cost of driving per mile is $0.42

PLEASE SOMEONE HELP ME WITH THIS! NO ONE CAN FIGURE IT OUT AND ILL GIVE YOU 60 POINTS PLUS BRAINLIEST IF YOU CAN HELP ME! please do not copy and paste or even comment just for the points, i really need help.

Answers

A) Variables:

X = number of weeks she puts money into the account.

Y = total amount in account after x weeks.

B) m would be the amount she puts in per week, b is the starting amount she has in the account

Y = 5x + 40

C) replace x with the x values in the cart and solve for y:

O : y = 40. Coordinates (0,40)

1: Y = 45. (1,45)

2: 50, (2,50)

3: 55, (3,55)

4: 60, (4,60)

D) make the graph using the above points

E) y intercept is when x is 0, which is 40. This was the starting value of how much money was saved.

Answer:

DO you still need help? Considering this was posted a long time ago.

Step-by-step explanation:

As the amount of time on homework increased, their grade in class ____________.

Answers

Answer:

Increases

Step by Step Explanation:

More time on your homework means more time to cheat/figure the answer out.

Answer:

Improved

Step-by-step explanation:

The more you study or do homework, the more you learn, and the better your grade

1. Lake Turkana is in the Great Rift Valley in northwest Kenya. As part of a study of water quality, the water temperature in the lake was measured at different depths. The data are shown in this scatter plot.

Answers

Answer:

a. 26° C

b. 40m

c. Yes

Step-by-step explanation:

I think your question is missed of key information, allow me to add in and hope it will fit the original one.  Please have a look at the attached photo.

a. What was the approximate temperature at a depth  of 70 m? At the surface?  

26° C

b. At what depth was the temperature  a little more than 27°C?

40 m

c. Do the points in the scatter plot show a relationship?  Explain your thinking.

Yes, the scatter plot show a relationship between the depth and the temperature of Lake Turkana. It shows a negative correlation between the two variables. The deeper the lake is, the cooler the temperature .

Hope it will find you well.

Find the area of the shaded segment. Round your answer to the nearest hundredth. ​

Answers

Answer:

2.57

Step-by-step explanation:

1/4×22/7×3×3=7.07

1/2×9=4.5

7.07-4.5=2.57

Vanessa draws one side of equilateral
△ABC on the coordinate plane at
points A(-2, 1) and B(4,1). What are
the two possible coordinates of vertex
C? Round to the nearest tenth.

Answers

Answer:

According to my calculation, the two possible coordinates of vertex C, is [tex](1,\sqrt{27}) and (1,-\sqrt{27})[/tex].

Answer:

According to my calculation, the two possible coordinates of vertex C, is .

Step-by-step explanation:

Jeremy caught 8 fish in a contest.
The mean weight of the fish was 4.3125 kg.
He forgot to make his own record of the weight of the last fish,
but the first 7 were: 4.3 kg, 5.3 kg, 6.8 kg, 2.6 kg, 3.2 kg, 4.4 kg and 4.8 kg
What was the weight of the last fish?
kg [2]

Answers

The weight of the last fish was 3.1 kg. It's found by subtracting the sum of the weights of the first 7 fish from the sum of all weights.

To find the weight of the last fish, we can use the mean weight formula:

[tex]\[\text{Mean weight} = \frac{\text{Sum of all weights}}{\text{Number of fish}}\][/tex]

Given:

- Jeremy caught 8 fish.

- The mean weight of the fish was 4.3125 kg.

- The sum of the weights of the first 7 fish is [tex]\(4.3 + 5.3 + 6.8 + 2.6 + 3.2 + 4.4 + 4.8\).[/tex]

First, let's calculate the sum of the weights of the first 7 fish:

[tex]\[4.3 + 5.3 + 6.8 + 2.6 + 3.2 + 4.4 + 4.8 = 31.4\text{ kg}\][/tex]

Now, let's find the sum of all weights of the 8 fish:

[tex]\[4.3125 \times 8 = 34.5\text{ kg}\][/tex]

To find the weight of the last fish, we subtract the sum of the weights of the first 7 fish from the sum of all weights:

[tex]\[34.5 - 31.4 = 3.1\text{ kg}\][/tex]

So, the weight of the last fish was 3.1 kg.

Emilce pide 5 platos por semana para almorzar en la oficina. El menú ofrece 5 opciones diferentes. De cuantas maneras puede realizar el pedido de la semana si quiere repartir los platos?

Answers

Answer:

120 different ways

Step-by-step explanation:

For the first lunch, Emilce has 5 options to choose,

In the second lunch, now she has only 4 options, as one was already chosen.

Then, in the third lunch, she has 3 options.

In the fourth lunch, she has 2 options.

In the last lunch, she has just 1 option.

So, the number of different ways she can order her lunches in the week is:

5 * 4 * 3 * 2 * 1 = 120

She can order in 120 different ways.

What is 7 more than five times the number 9 divided by 15?

Answers

Answer:

10

Step-by-step explanation:

The number of laughs (denoted by L) can be defined as a function of the number of jokes (denoted by J), the amount of knowledge about the joke material (denoted by K), and the familiarity with the jokes (denoted by F) using this formula: L=J⋅K2F L, equals, start fraction, J, dot, K, squared, divided by, F, end fraction Select an appropriate measurement unit for number of laughs.

Answers

Answer:

(A) [tex](Jokes * Knowledge^2) / Familiarity[/tex]

Step-by-step explanation:

The number of laughs (denoted by L) is a function of

The number of jokes (denoted by J), The amount of knowledge about the joke material (denoted by K).

Given [tex]L=\frac{J\cdot K^2}{F}[/tex]

The appropriate measurement unit for number of laughs will be:

[tex](Jokes * Knowledge^2) / Familiarity[/tex]

The results for a survey of 120 students who were selected randomly are as follows 60 students have a cell phone plan with company x. 36 students have a cell phone plan with company y. 24 students do not have a cell phone the total population of students was 380.Based on the data what is the best approximation for the total number of students who have a cell phone plan with company y?

Answers

Answer:

114

Step-by-step explanation:

find the solution below

An animal pen is in the shape of a triangle. One of the interior angles of the triangle is 40 degrees. The measure of the other interior angles are in the ratio 3 : 5. What are the measures of the other interior angles?

Answers

Final answer:

In a triangle, the sum of all interior angles is always 180 degrees. Given the ratio of the other interior angles, we can find their measures.

Explanation:

In a triangle, the sum of all interior angles is always 180 degrees. Given that one of the interior angles is 40 degrees, let's denote the measures of the other two angles as 3x and 5x. The sum of all three angles is 40 + 3x + 5x = 180. Simplifying this equation, we get 8x + 40 = 180. Subtracting 40 from both sides gives us 8x = 140. Dividing both sides by 8, we find x = 17.5.

Now, we can substitute the value of x back into the expressions for the other two angles. So, the first angle is 3x = 3(17.5) = 52.5 degrees, and the second angle is 5x = 5(17.5) = 87.5 degrees.

Mary bought 3 cartons of milk for $1.06 each. If she paid for the milk with a five-dollar bill, how much money should she get back​

Answers

Answer:

shed get $1.82 back

Step-by-step explanation:

Answer:

She would get $1.82 back

Step-by-step explanation:

If she bought 3 cartons costing $1.06 each, you would have to multiply $1.06 by 3

$1.06 x 3 = $3.18

Then if she paid with a five dollar bill you have to subtract $3.18 from 5

5 - 3.18 = 1.82

$1.82 is the answer

What is the factored form of the polynomial 27x²y - 43xy??
xy(27x – 43y)
x?y?(27 – 43)
3xy(9x – 17y)
3x?y(9 – 14y)

Answers

This is the questions Xy(27x-43y) :)

Answer: xy (27x - 43y)

Step-by-step explanation:

I need help asap i am confused

Answers

Answer:

the top one (-40)8 is the correct answer

The daily high temperatures in Philadelphia for the first 15 days in February is normally distributed with a standard deviation of 2.5°. If it was 37° on Valentine's Day with a z-score of 2.4, the mean temperature is _________°.Immersive Reader

Answers

Answer:

The mean temperature is 31.

Step-by-step explanation:

The formula for the z-sore is

          x - mean

z = ----------------------

        (std dev)

In this case let's multiply both sides by (std dev), obtaining:

x - mean = z*(std dev).

Solving for (mean), we get

mean = x - z*(std dev)

Substituing 37 for x, 2.4 for z and 2.5 for (std dev), we get:

mean = 37 - (2.4)(2.5) = 31

The mean temperature is 31.

Final answer:

To find the mean temperature with the given z-score and standard deviation, the z-score formula is used. After calculation, the mean temperature in Philadelphia for the first 15 days of February is determined to be 31°.

Explanation:

The question is asking us to find the mean temperature in Philadelphia for the first 15 days in February, given that the daily high temperatures are normally distributed with a standard deviation of 2.5° and that on Valentine's Day (February 14th), the temperature was 37° with a z-score of 2.4. To solve for the mean temperature, we can use the z-score formula:

Z = (X - μ) / σ

Where:
Z is the z-score,
X is the value in the dataset,
μ is the mean, and
σ is the standard deviation.

We know Z = 2.4, X = 37°, and σ = 2.5°. Plugging these values into the z-score formula, we can solve for the mean (μ).

2.4 = (37 - μ) / 2.5

Multiplying both sides by 2.5, we get:

2.4 x  2.5 = 37 - μ
6 = 37 - μ
μ = 37 - 6
μ = 31°

Therefore, the mean temperature in Philadelphia for the first 15 days in February is 31°.

The points ​(2​,10​) and ​(minus2​,minus10​) are plotted on the coordinate plane using the equation yequalsatimesx. How can you use the coordinates to find the value of​ a? Select the correct answer​ below, and fill in the answer box to complete your choice. ​(Type a whole​ number.) A. The value of a is the number that the​ y-values are multiplied by to get to the corresponding​ x-values. So, aequals nothing. B. The value of a is the absolute value of the difference of the​ y-values. So, aequals nothing. C. The value of a is the number that the​ x-values are multiplied by to get to the corresponding​ y-values. So, aequals nothing. D. The value of a is the absolute value of the difference of the​ x-values. So, aequals nothing.

Answers

Answer: The value of a is the number that the​ x-values are multiplied by to get to the corresponding​ y-values. So, a equals 5

We have

y=ax  

so a is clearly the number we multiply by the x values.

Substituting either  points (2,10) and (-2,-10),

10 = a(2)

a = 10/2 = 5

Other Questions
You receive the following prescription:Jim TuckerDispense four (4) weeks supply.lamivudine one hundred fifty(150) mg bid # _zidovudine three hundred (300)mg bid # _a. How many of each will you dispense?b. What might be the patients diagnosis?please help What is the Pythagorean Therom We are currently designing three new product lines for 2014: picnic tables, lawn chairs, and benches. These products are comfortable and beautifully designed. We intend to have them ready for production by June. These products have been met with positive reviews from our test customers, and we believe they will increase our profit margin by another 25 percent. [4] We will have our sample products from the new lines in our showroom next week. I am eager to show you how beautiful they are. You are invited to be our special guest for a product launch party on May 22; I will phone you on Friday, May 16, to confirm that you will attend. Sincerely yours, Joseph Pelletier What is effective about the opening of this message? Check all that apply. A. Gains attention B. Uses a direct pattern C. Uses an interesting fact D. Sounds preachy or parental Label the words shown in bold.The quick lizard easily caught the bug.Label them as adjective and/or adverb!! Need help immediately if possible!! A population of 15 birds inhabits a fairly new island. Ten of the birds are dark brown and five of them are light brown. By chance, two of the dark brown birds and three of the light brown birds die before producing any offspring. All of the birds in the next generation are dark brown. This change in phenotypic frequency can be attributed to _____. quilet What is 75k industry into a percent? The answer for the problem The Petersons hotel has a lazy river that is shaped like a circle with a diameter of 120 ft. If mr. Peterson has made one full rotation how many feet has he traveled? Need help with this Simplify -3 1/2 - (-12 1/4) Fill the blank with the conditional form of the verb.1) Los boletos del concierto _______(deber) ser ms baratos. 2) Yo (cambiar) de canal, pero a mi madre le encanta este concurso. 3) Por qu razn _______(ellos) no _______(elegir) a Marta para hacer el papel principal? 4) Nosotros no _______(pagar) por ver esa pelcula, tiene muy mala crtica. 5) Vamos a ver una comedia, creo que a ti te _______(gustar) ms que la pera. Ron wants to buy a video game with a selling price of $48. It is on sale for 50% off. 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The following information relates to Carried Away Hot Air Balloons, Inc.: Advertising Costs $ 15 comma 800 Sales Salary 13 comma 800 Sales Revenue 650 comma 000 President's Salary 52 comma 000 Office Rent 66 comma 000 Manufacturing Equipment Depreciation 1 comma 000 Indirect Materials Used 8 comma 300 Indirect Labor 11 comma 100 Factory Repair and Maintenance 800 Direct Materials Used 22 comma 410 Direct Labor 35 comma 600 Delivery Vehicle Depreciation 940 Administrative Salaries 25 comma 000 How much was Carried Away's manufacturing overhead? 19.EL CONDENADO A MUERTE. En los tiempos de la antigedad la gracia o el castigo se dejaban frecuentemente al azar. As, ste es el caso de un reo al que un sultn decidi que se salvase o muriese sacando al azar una papeleta de entre dos posibles: una con la sentencia "muerte", la otra con la palabra "vida", indicando gracia. Lo malo es que el Gran Visir, que deseaba que el acusado muriese, hizo que en las dos papeletas se escribiese la palabra "muerte". Cmo se las arregl el reo, enterado de la trama del Gran Visir, para estar seguro de salvarse? Al reo no le estaba permitido hablar y descubrir as el enredo del Visir. Group the following electronic configurations of neutral elements in sets according to those you would expect to show similar chemical properties.a. 1s^22s^22p^63s^23p^3b. 1s^22s^22p^63s^23p^63d^104s^24p^5c. 1s^22s^22p^63s^23p^6d. 1s^22s^22p^3 An agency relationship between a broker and a seller A. requires a written agency agreement. B. requires a verbal agency agreement. C. requires a deposit good faith money. D. must be approved by the Colorado Real Estate Committee. Rico wants to find the distance between the points (-2,-3) and (2,-5) his work is shown.|-3| + |-5| = 3+5 = 8the distance is 8 unitsis Riko correct explain why or why not?