Suppose that the test score of a student taking the final of a probability course is a random variable with mean 76.

Required:
a. Give an upper bound for the probability that a student's test score will exceed 86. Suppose, in addition, that the professor knows that the variance of a student’s test score is equal to 25.
(b) What can be said about the probability that a student will score between 65 and 85?
c. How many students would have to take the examination to ensure, with probability at least .9, that the class average would be within 5 of 75? Do not use the central limit theorem.

Answers

Answer 1

Answer:

a. 0.8837

b. 0.6914

c. 10 student

Step-by-step explanation:

a. using markov's inequality; P(u >= X)<= E(u) / X

   mean u = 76

   X, test score = 86

= 76 / 86 = 0.8837

b. variance v = 25

   The test is between 65 and 85 P(65 <= X <= 85);

   P(|65 - X|<= |X - u| <= |85 - X|) = P(65 - 76 <= |X - u| <= 85 -76)

   = P(-11 <= |X - u| <= 9)

   = P(|X - u| <= 9)

using the chebyshev's inequality;

P(|X - u| <= 9) = 1 - variance / (standard deviation of individual test score)^2

   = 1 - 25/ 9^2

   = 1 - 25/81 = 1 - 0.3086 = 0.6914

c. P(|X - 76| <= 5) = 0.9

still using chebyshev's inequality;

= 1 - variance / lower limit^2 (E)

where E = 1 - 0.9 = 0.1

lower limit = 5

= 1 - 25/ 5^2 (0.1) = 10


Related Questions

Write an equation of the line that passes through (7,10) and is perpendicular to the line y=12x−9.

Answers

Answer:

y = - [tex]\frac{1}{12}[/tex] x + [tex]\frac{127}{12}[/tex]

Step-by-step explanation:

y = 12x - 9

Slope of line perpendicular to given is m = - [tex]\frac{1}{12}[/tex]

P(7, 10)

y - 10 = - [tex]\frac{1}{12}[/tex] (x - 7)

y = - [tex]\frac{1}{12}[/tex] x + [tex]\frac{127}{12}[/tex]

An equation of the line that passes through (7,10) and is perpendicular to the line y=12x−9 is y - 10 = -1/12(x-7)

The equation of a line in point-slope form is expressed as;

y - y0 = m(x-x0)

m is the slope of the line(x0, y0) is any point on the line

Given the equation of a line y = 12x - 9

Slope = 12Slope of the line perpendicular is -1/12

Substitute m = -1/12 and ()7, 10) into the equation above to have;

y - 10 = -1/12(x-7)

Hence an equation of the line that passes through (7,10) and is perpendicular to the line y=12x−9 is y - 10 = -1/12(x-7)

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A survey of U.S. adults found that 67% oppose raising the Medicare eligibility age from 65 to 67. You randomly select 80 U.S. adults S and ask them how they feel about raising the Medicare eligibility age from 65 to 67. Find the probability that the number who oppose raising the age is (a) at least 65, (b) exactly 50, and (c) more than 60, and (d) identify any unusual events. Explain.

Answers

Answer:

0.477%

6.55%

5.05%

Event in question (a)

Step-by-step explanation:

Given that:

p = 0.67 ; n = 80

Using Normal approximation :

Mean (m) = np = 80 * 0.67 = 53.6

Standard deviation (s) = sqrt(np(1-p)) = sqrt(80*0.67*0.33) = 4.2057

probability that the number who oppose raising the age is

(a) at least 65

65 - 0.5 = 64.5 = x

Z = (x - m) / s

Z = (64.5 - 53.6) / 4.2057 = 2.592

P(Z ≥ 2. 592) = 0.004771 (Z probability calculator)

(b) exactly 50

x = 50 + 0.5 = 50.5 ; x = 50 - 0.5 = 49.5

Z = (50.5 - 53.6) / 4.2057 = - 0.737

Z = (49.5 - 53.6) / 4.2057 = - 0.974

P(Z < - 0.737) - p(Z < 0.974) (Z probability calculator)

0.23056 - 0.16503 = 0.06553

(c) more than 60, and (d) identify any unusual events

x = 60 + 0.5 = 60.5

Z = (60.5 - 53.6) / 4.2057 = 1.64

P(Z > 1.64) = 0.0505

D.) Event with probability of less than 5%, which is event in (a) with probability of 0.477%

At Barlow school, 4/9 of the 873 students are boys. At Willow school, 2/3 of the 630 students are girls
Which school has a greater of boys and how many?

Answers

Answer:

I have attached the answer

Alfie is cooking a 0.6kg jaunt of steak for dinner. calculate the total time he needs to cook for it ​

Answers

Answer: This is a tough question

Depends on if you wanna cook it medium rare, rare, medium well, well done, or do you just wanna eat it raw :D

Step-by-step explanation:

a farmer grows 128 red tomato plants and 102 yellow tomato plants each plant produces about 32 tomatoes the farmer plans to sell each tomato for$2

Answers

Answer:

14720$ he will make and there are 7360 tomatoes

Step-by-step explanation:

How to solve
3sin^2x-5sinx-2

Answers

So not commit sins
Become one with the lord
Read the bible
Too many sins
Ask the lord for forgiveness
Thats how you solve you answer
Explanation
Listed above
Bababoey

Is this a function?

Answers

Answer:

It isn't a function.

Step-by-step explanation:

Since there are two points on the same x value, in this case x=3, this means that these points can not be a function.

Find the angle θ between vectors r and s, where |r| = 16, |s| = 9, and r · s = 125. θ = 85.87° θ = 82.65° θ = 29.77° θ = 16.26°

Answers

Answer:

C - 29.77

Step-by-step explanation:

Edge 2020

Multiplication is the process of multiplying, therefore, adding a number to itself for the number of times stated. The angle θ between vectors r and s is 29.766°.

What is multiplication?

Multiplication is the process of multiplying, therefore, adding a number to itself for the number of times stated. For example, 3 × 4 means 3 is added to itself 4 times, and vice versa for the other number.

The product of two vectors is written as,

[tex]r \cdot s = |r|\cdot |s| \times \cos(\hat I)[/tex]

Substituting the values,

125 = 16 · 9 × Cos(θ)

0.868 = Cos(θ)

θ = 29.766°

Hence,  the angle θ between vectors r and s is 29.766°.

Learn more about Multiplication:

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If p varies jointly as q and the cube of r, when
p=270 when q=6 and r=3, find the constant of
variation. Write your answer as a fraction.
y=kxz

Answers

Hope this might help u

The value of constant of variation is, 5.

What is Proportional?

Any relationship that is always in the same ratio and quantity which vary directly with each other is called the proportional.

Given that;

⇒ p varies jointly as q and the cube of r.

Since, p varies jointly as q and the cube of r.

Hence, We can formulate;

⇒ p = k × q × r²

Where, k is constant of variation.

Here, p = 270 when q = 6 and r = 3.

Substitute all the values, we get;

⇒ p = k × q × r²

⇒ 270 = k × 6 × 3²

⇒ 270 = 54k

⇒ k = 270 / 54

⇒ k = 5

Learn more about the proportion visit:

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What is this? Please answer with an explanation

Answers

At 5 and you do this by setting the inside equal to 0 and solving for x

Answer:

x=9,30............etc

Step-by-step explanation:

if value of x=9 then

the function

value of f(x)=4

if x=30 then value of function f(x)=27

What is the distance between -23 and 6

Answers

Answer:

29

Step-by-step explanation:

add 23 to cancel the negative then add 6 to get the final answer

Answer:

29 units.

Step-by-step explanation:

The distance is  6 - (-23)

= 6 + 23

= 29 units.

Please can someone help me please
It is attached

Answers

the answer is 1! I hope this is right
Simplify the expression

(y+1)^3

Using , (a+b)^3=a^3a^2b+3ab^2+b^3expand the expression

y^3+3y^2+3y+1=
Answer

How many points will I get if I get 60 points every 5 mins and it goes on for 4 hours?

Answers

Answer:

well u multiply 60 and 12 which is 720 then multiply that by 4 that equals 2,880 more points

60/5=12 every minute you get 12 points so 4 hours=240mins which concludes that 240*12=2880 points

Hope this helps

Have a great day/night

A circular tablecloth has a diameter of 6 feet,as show on the picture.



What is the area,in square feet,of the tablecloth.​

Answers

Nsnsnanannajakaabaatayqqjabwhwwkk

What is the equation of the line that passes through the point -4 and four and has a slope of -3

Answers

That will be -1 Bc u are subtracting

Answer:

y = -3x-8

Step-by-step explanation:

(-4 ,4)

4 = -3(-4) + b

4 = 12 + b

b = -8

y = -3x-8

Help Please, im stuck on this question.

Answers

Answer:

irrational

Step-by-step explanation:

3/4 + sqrt(2)

3/4 is rational

sqrt(2) is irrational

The sum of a rational and an irrational number is irrational

I need help on this onee pleasee

Answers

Answer:

1. 2nd row multiplied by the 3 columns : 7x³ , -35 x²,42

2. 3rd row multiplied by the 3 columns :  -4x² , 20x ,-24

Step-by-step explanation:

The table requires you to perform multiplication of the terms

The product is as follows;

1. 2nd row multiplied by the 3 columns

7x * x² = 7x³

7x * -5x = -35 x²

7x * 6 = 42

2. 3rd row multiplied by the 3 columns

-4 * x² = -4x²

-4 * -5x = 20x

-4*6 = -24

The explains why a x b = b x a and a + b = b + a.

Answers

Answer: The commutative property

Explanation: the commutative property of addition/multiplication states that no matter what order the expression is in it will equal the same thing.

Determined to find the slope
(1 7K), and (-3,5K)​

Answers

Answer: [tex]\dfrac{K}{2}[/tex] .

Step-by-step explanation:

As we know ,

The slope of a line that passes through [tex](x_1,y_1)[/tex] and [tex](x_2,y_2)[/tex]  is given by :

[tex]\dfrac{y_2-y_1}{x_2-x_1}[/tex]

The slope of a line that passes through (1 , 7K), and (-3,5K)​ =

[tex]\dfrac{5K-7K}{-3-1}\\\\=\dfrac{-2K}{-4}\\\\=\dfrac{K}{2}[/tex]

Hence, the slope of the given line is [tex]\dfrac{K}{2}[/tex] .

Each of four test scores in Connie’s class is to be weighted equally. On the first three tests, Connie scored 80%, 90% and 95%. What percent must she score on her fourth test to have an overall average of exactly 90%?

Answers

Answer:

95%is the answer

Step-by-step explanation:

Answer:

95%

Step-by-step explanation:

We can use the balancing method to do this.. first what is the total below 90?

The total is 10% because 90-80 which was the only percentage below 90 is 10%. Then, what is the total above 90?

The total is 5% because the only percentage above 90 is 95 and 95-90 is 5%

Now we use the balancing method to get from 5-10.

Using the balancing method we get 95%

please answer these questions ​

Answers

Step-by-step explanation:

you need to multiple first by second

2 L = _____ ml can someone help? :((

Answers

Answer:

2000

Step-by-step explanation:

Answer:

2000 ml

Step-by-step explanation:

Lee is making scarfs for a shelter. He purchased 11 skeins of yarns. Each skein has 660 feet of yarn. He needs 200 yards of yarn to make one scarf.

Answers

Answer:

Give me sum

Step-by-step explanation:

Answer:

Most scarves will use one to two skeins of yarn. According to the chart above, you will probably need about 300–650 yards, depending on the weight of yarn, the colors, the stitches, style, and length amongst other factors.

Step-by-step explanation:

Julie Myrick has a credit card that has an APR of 15%, applied at a daily
periodic rate to the previous balance. Her previous balance is $567,31. She made
new purchases totaling S128.92, and a payment-of $125 in the month of June.
What is her new balance?

Answers

Answer.    332.78

Step-by-step explanation:

I subtracted and as awesome its right trust me.

ASE
BCDE is a trapezium with angle CDE = 90°. ABEF is a straight line.
Q2)
D
Diagram
accurately
1159
А
11030
E
F
B
Work out the size of the angle marked x.

Answers

Answer:

128 deg

Step-by-step explanation:

The sum of the measures of the angles of a polygon of n sides is

(n - 2)180

A trapezium has 4 sides, so the sum of the measures of the angles is

(4 - 2)180 = 2(180) = 360

m<CBE + m<C + m<D + m<DEB = 360

Angles ABC and CBE are a linear pair so the sum of their measures is 180 deg.

m<ABC + m<CBE = 180

115 + m<CBE = 180

m<CBE = 65

m<C = x

m<D = 90

Angles DEB and DEF are a linear pair so the sum of their measures is 180 deg.

m<DEB + m<DEF = 180

m<DEB + m<103 = 180

m<DEB = 77

m<CBE + m<C + m<D + m<DEB = 360

65 + x + 90 + 77 = 360

x + 232 = 360

x = 128

Answer: 128 deg

so we will get a lot of teiangles here.

90°+x+CED=180°

also CED+DEF=180°(half circle, 360/2)

CED+103°=180°

CED=180-103=77°

77°+90°+X/2=180°

x/2=180-167=13°

of the following pair of variables indicate whether you would expect a positive, negative, or no correlation to exist.
Maximum daily temperature and cost to coolant house​

Answers

Answer:

B

Step-by-step explanation:

Bbbbb bbbbbbbbbbb

The graph represents function 1, and the equation represents function 2:
6
3
2
1
0
0 1
2
3
4
5 6 7 8 9
Function 2
y = 8x + 12
How much more is the rate of change of function 2 than the rate of change of function 1? (4 points)
O 3
O4
O 5

Answers

Answer:

Please check the explanation.

Step-by-step explanation:

We know that the slope or rate of change of the function can be:

positivenegativezero, orundefined

Function 1

From the function 1 graph, it is clear that the graph is a horizontal line. We must note that the horizontal line has a slope or rate of change zero. The reason is that the horizontal line can not rise vertically. i.e. y₂-y₁=0

so using the slope formula

Rate of change = m = y₂-y₁ / x₂-x₁

Taking two points (x₁, y₁) = (0, 4), (x₂, x₁) = (1, 4)

Rate of change = m = 4-4 / 1-0

Rate of change = m = 0/1

Rate of change = m = 0

Thus, the rate of change of function 1 is zero.

Function 2

We know the slope-intercept form of linear equation is

[tex]y = mx+b[/tex]

where m is the rate of change or slope of the function and b is the y-intercept

Given the function

[tex]y = 8x+12[/tex]

comparing with the slope-intercept form i.e. y = mx+b

Therefore, the rate of change of function 2 = m = 8

Conclusion

The rate of change of function 1  = 0

The rate of change of function 2  = 8

as

8 - 0 = 8

Therefore, function 2 has 8 more rate of change of function than the rate of change of function 1.

The following are the last 10 run scores Colin got in cricket: 1, 16, 5, 25, 26, 32, 5, 7, 1, 7 a) Work out Colin's mean score. b) Colin plays cricket again on Sunday. He gets 29 runs. What is his new mean score? Give your answers as decimals.

Answers

Answer:

a. 12.5   b. 14

Step-by-step explanation:

If you add all of the scores together (125) and then divide by the the number of scores in the sequence (10), you get 12.5, and then you need to add the 29 on to 125 and divide that by 11, because thats the new amount of numbers in the sequence, to get 14.

Help me please and thank you

Answers

Answer:

ΔMXP, ΔXMP, ΔPMX

Step-by-step explanation:

A triangle has three sides and three points, so it can only be named using the three points, X, P and M.

Find the length of AB PLEASE HELP

Answers

Answer: D) 53.74

This value is approximate.

===========================================

Work Shown:

x = length of AB

Use the sine rule to say

sin(angle) = opposite/hypotenuse

sin(B) = AC/AB

sin(61) = 47/x

x*sin(61) = 47

x = 47/sin(61)

x = 53.7376 ..... make sure your calculator is in degree mode

x = 53.74

So AB = 53.74 approximately

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