You receive an A 40% of the time, a B 20% of the time, a C 15% of the time , and a D the rest of the time. For any random test, what is your expected grade point average? (Use the following values for X: A=4, B=3, C=2, D=1)

Answers

Answer 1

The grade you receive on a test is a discrete random variable with probability mass function

[tex]f_X(x)=P(X=x)=\begin{cases}0.4&\text{for }X=4\text{ (i.e. scoring an A)}\\0.2&\text{for }X=3\text{ (B)}\\0.15&\text{for }X=2\text{ (C)}\\0.25&\text{for }X=1\text{ (D)}\\0&\text{otherwise}\end{cases}[/tex]

where the probability of getting a D is 25% because there are only 4 possible grades, and the probabilities must sum to 1 :

0.4 + 0.2 + 0.15 + 0.25 = 1

The expected test score/GPA is then

[tex]\displaystyle\sum_x x\,f_X(x)=\sum_{x=1}^4 x\,P(X=x)=1\cdot0.25+2\cdot0.15+3\cdot0.2+4\cdot0.4=\boxed{2.75}[/tex]

so your average would fall between a B and a C.


Related Questions

Find the value of x that makes the equation true
3 ( x- 8 ) + 2x = 76

Answers

Answer:

x = 20

Step-by-step explanation:

3 (x-8) +2x = 76

3x - 24 +2x = 76

3x+2x = 76+24

5x = 100

x = 20

A car rental company charges $34 per day for a rented car and $0.50 for every mile driven. A second car rental company charges $20 per day and $0.75 for every mile driven. What is the number of miles at which both companies charge the same amount for a one-day rental?

A.
56 miles

B.
54 miles

C.
36 miles

D.
24 miles

Answers

Answer:

B 2/3

Step-by-step explanation:

:)

First you want to make the equations for finding the total price of each rental car. We will say that x is the number of days and y is the number of miles. We will say the price for the first company is A = 34x + 0.50y and the second company is B = 20x + 0.75y. We want to find y where 34x+0.5y = 20x+0.75y and x=1. You should get 56 miles

HELLP
What is the formula for finding the perimeter of a polygon?

Answers

Answer:

P=n*s

Step-by-step explanation:

n is the number of sides and s is the length of any one side.

Answer:

It depends on the polygon.

Perimeter is the distance around a figure, so the formula changes for what type of polygon it is. For example, a square would be 4l or the length of one side times 4.

To find the perimeter for any polygon, regular or irregular, use the distance formula for each side. Then add all values together.

The distance formula is [tex]\sqrt{(x_2 - x_1)^2 + (y_2 - y_1)^2}[/tex]

Where [tex](x,y)[/tex] is one edge and [tex](x_2 , y_2)[/tex] is another edge, both belonging to the same side. This formula calculates the unit length of a side of your choice. For irregular figures, you have to use this formula for every side. For regular figures, just multiply the distance by how many sides there are.

Distance calculator for 2d grid: https://www.calculatorsoup.com/calculators/geometry-plane/distance-two-points.php

Distance formula explanation: https://www.khanacademy.org/math/geometry/hs-geo-analytic-geometry/hs-geo-distance-and-midpoints/v/distance-formula#:~:text=Learn%20how%20to%20find%20the,distance%20between%20any%20two%20points.

Write down the inequality for x that is shown on this line

Answers

Answer:

x > 3

Step-by-step explanation:

Open circle and going to the right inequality: >

Since it starts at 3, the inequality is:

x > 3

The required inequality will be 3<x<7.

What is an inequality?

It is a type of equation having less than and greater than signs.

How to form an inequality?

If we see the line it is started from 3 and ends on 7 and circle on 3 is not filled it means it does not contains 3 So the required inequality is

3<x<7

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A jacket with an original price of $67.80 is discounted 10%. What is the sale price?

Answers

I’m pretty sure it is $61.02

The function p(x) = –2(x – 9)2 + 100 is used to determine the profit on T-shirts sold for x dollars. What would the profit from sales be if the price of the T-shirts were $15 apiece?

$15
$28
$172
$244

Answers

Answer:

the answer is 28

Step-by-step explanation:

i know this because i got it wrong and it told me

help me plzz plzz pleases ​

Answers

Answer:

Look at the image I included

what is 10 x 567 divded by 2 x 45

Answers

Answer:

63

Step-by-step explanation:

Answer: 63

Step-by-step explanation: First, you would do 10 x 567.

10 x 500 = 5000

10 x 60 = 600

10 x 7 = 70

5000 + 600 + 70 = 5670

Next, you find out 2 x 45.

2 x 45 is equivalent to 45 + 45.

45 + 45 = 90

Finally, you divide the product by the product - 5670 divided by 90.

The answer to that is 63.

What is the vertex of f(x) = |x + 8| – 3?
(-8,-3)
(-8,3)
(8,-3)
(8,3)

Answers

What is the vertex of f(x)=|-8,-3|-3?

Answer: A.(-8,-3)

The vertex of the function f(x) = |x + 8| - 3 is (-8, -3).

What is an Equation?

An equation is the statement of two expressions located on two sides connected with an equal to sign. The two sides of an equation is usually called as left hand side and right hand side.

Given is an absolute value function,

f(x) = |x + 8| – 3

For a function of the form,

f(X) = a |x - h| + k, the vertex of the function is the point (h, k).

Comparing the equation with the given one,

f(x) = |x + 8| – 3

f(x) = |x - (-8)| + (-3)

So we get, h = -8 and k = -3.

So vertex is (-8, -3).

Hence the vertex is (-8, -3).

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f(x)=x^2−10x+21 in factored form

Answers

Answer:

(x-7)(x-3)

Step-by-step explanation:

The factored form of f(x)=x^2-10x+21 is (x-7)(x-3). In order to find the factored form, you have to find what values add to -10, yet multiply to 21. So, the values that add to -10 and multiply to 21 are -7 and -3. x and x multiply to x^2.

In conclusion, the factored form of f(x)=x^2-10x+21 is (x-7)(x-3).

find the product (please list step by step)

( 4x^{7}y^{2} ) ( 3x^{3} y^{2} )

Answers

Answer:

The answer is 12x¹⁰y⁴.

Hope this helped!!

Step-by-step explanation:

1. ( 4x⁷y² ) ( 3x³y²)

2.  4x⁷y² ₓ  3x³y²

No links please I need help ASAP
The drama club sells tickets to their spring play. They sell 180 tickets for a
total of $2,248. Adult tickets cost $14 each. Student tickets cost $10 each.
How many adult tickets and how many student tickets do they sell?
Show your work.

Answers

The number of adult and student tickets are 112 and 68 respectively

How to determine the number of adult and student tickets?

Word problems are sentences describing a 'real-life' situation where a problem needs to be solved by way of a mathematical calculation.

Set up equations to represent the problem.

Let the A and S represent the numbers of adult and student ticket respectively. So we can write:

A + S = 180 --- (1)

14A + 10S = 2248  --- (2)

From (1):

A = 180 - S ----(3)

Put (3) in (2):

14A + 10S = 2248

14(180 - S) + 10S = 2248

2520 - 14S + 10S = 2248

2520 - 4S = 2248

4S =  2520 - 2248

4S = 272

S = 272/4

S = 68

Put S = 68 in (3):

A = 180 - S

A = 180 - 68

A = 112

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i posted 2 others already plz help answer i really need this

Answers

Answer:No

Step-by-step explanation:

B. No ;):););):);););):p

What is m∠1? Help me, please

Answers

Answer:

32°

Step-by-step explanation:

Since the 147° angle and ∠2 form a Linear pair, sum of these angle must be 180°

147° + ∠2 = 180°

∠2 = 180° - 147°                       [subtracting 147° from both sides]

∠2 = 33°

Since all internal angles of a triangle add up to 180°,

∠1 + ∠2 + 115° = 180°

∠1 + 33° + 115° = 180°

∠1 + 148° = 180°

∠1 = 180° - 148°                       [subtracting 148 from both sides]

∠1 = 32°

The cost of a taxi ride is given by the function C(x)=0.75x +2,
where x=distance in miles and C(x)=total cost in dollars.
What are the domain and range of C(x) in this situation?

Answers

Answer:

(

)

=

0

.

7

5

+

2

Step-by-step explanation:

Find the y-intercept of the line which passes through (-2,-2) and (2,-4).

Answers

Your Y- intercept is -3

Simplify the expression to a + bi form:
(-8 – 9i)2

Answers

Answer:

-17+144i

Step-by-step explanation:

Chicago, Illinois, has an elevation of 600 feet above sea level. The elevation of Desert Shores, California, is 800 feet less than the elevation of Chicago. Select all options that apply to Desert Shores. *

elevation of –200 feet
elevation of 200 feet
below sea level
at sea level
above sea level

Answers

Answer:

elevation of –200 feet  

below sea level

Step-by-step explanation

600-800=-200

For what values of theta, °

Answers

Answer:

Step-by-step explanation:

A fish is swimming at a constant rate toward the ocean floor. The equation y=-7x-3 can be used to represent this situation, where y is the depth of the fish in meters below sea level and x is the number of seconds the fish has been swimming. Which statement best describes the depth of the fish, given this equation?

A. From a starting point of 7 meters below sea level, the fish is descending 3 meters per second.

B. From a starting point of 7 meters below sea level, the fish ascending 3 meters per second.

C. From a starting point of 3 meters below sea level, the fish is descending 7 meters per second.

D. From a starting point of 3 meters below sea level, the fish is ascending 7 meters per second.​

Answers

Answer:

i think the answer is either c or d, but since the 7 is negative, i'd try c first.

Step-by-step explanation:

tell me if this is wrong.

Learning math. The Core Plus Mathematics Project (CPMP) is an innovative approach to teaching mathematics that engages students in group investigations and mathematical modeling. After field tests in 36 high schools over a three-year period, researchers compared the perfor­mances of CPMP students with those taught using a traditional curriculum. In one test, students had to solve applied algebra problems using calculators. Scores for 320 CPMP students were compared with those of a control group of 273 students in a traditional math program. Computer software was used to create a confidence interval for the difference in mean scores (Journal for Research in Mathematics Education, 31, no. 3, 2000).
Conf. level: 95%

Variable: µ(CPMP) — µ(Ctrl)

Interval: (5.573, 11.427)

a) What is the margin of error for this confidence interval?

b) If we had created a 98% confidence interval, would the margin of error be larger or smaller?

c) Explain what the calculated interval means in this con­text.

d) Does this result suggest that students who learn mathe­matics with CPMP will have significantly higher mean scores in applied algebra than those in traditional programs? Explain.

Answers

Answer:

D is the answer

Step-by-step explanation:

A Ferris wheel has a diameter of 90 feet. If a rider starts at the bottom of the wheel, how many feet does the rider travel after one full turn of the wheel? Record your answer in the boxes. Then fill in the bubbles. Be sure to use the correct place value.​

Answers

Answer:

I dont get the question :(

Help please on this asap

Answers

It is a

Scalene and Right angle

What is the approximate value of tan C?
B
13.93
A
3
A. 0.38
B. 0.36
C. 0.93
D. 2.6

Answers

Answer:

0.38

Step-by-step explanation:

What is the volume of the cylinder? Hint: the radius is 2ft in this problem

Answers

Answer: 37.68 ft^3

Step-by-step explanation:

Pi = 3.14

Height = 3

Radius = 4/2

3.14 * 3 * (4/2)^2

=37.68

If you want it in Pi, it's just 12[tex]\pi[/tex]

Which polygons are NOT quadrilaterals? Select THREE that apply.

Answers

Answer:

a cylinder, a sphere, and that little half sphere thing, oh and a triangular pyramid

Step-by-step explanation:


Which graph des NOT pass the vertical line test?

Answers

Graph 1
It fails because it intercepts the vertical line in 2 spots

What integer values satisfy both inequalities? − 2 < x < 3 − 2 ≤ x ≤ 2

Answers

Answer:

-1, 0, 1, 2

Step-by-step explanation:

range of x in − 2 < x < 3:  -1, 0, 1, 2

range of x in − 2 ≤ x ≤ 2:  -2, -1, 0, 1, 2

Can someone tell me if this is a adjacent ,vertical or linear

Answers

Answer:

linear

Step-by-step explanation:

Two angles are said to be linear if they are adjacent angles formed by two intersecting lines.

sum of angles on a straight line is 180° thus linear angle is also be 180° when the two angles a and b combine

A number rounded to the nearest thousand is 400,000. The same number rounded to the nearest ten thousand is 350,000. What could be the number

Answers

i  think the numbers are the same

Answer:

i think the answer is 354,900.

Step-by-step explanation:

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