In determining automobile-mileage ratings, it was found that the mpg (X) for a certain model is normally distributed, with a mean of 33 mpg and a standard deviation of 1.7 mpg. Find the following:__________.
a. P(X<30)
b. P(28 c. P(X>35)
d. P(X>31)
e. the mileage rating that the upper 5% of cars achieve.

Answers

Answer 1

Answer:

a) P(X < 30) = 0.0392.

b) P(28 < X < 32) = 0.2760

c) P(X > 35) = 0.1190

d) P(X > 31) = 0.8810

e) At least 35.7965 mpg

Step-by-step explanation:

Problems of normally distributed samples are solved using the z-score formula.

In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the zscore of a measure X is given by:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

In this question, we have that:

[tex]\mu = 33, \sigma = 1.7[/tex]

a. P(X<30)

This is the pvalue of Z when X = 30. So

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]Z = \frac{30 - 33}{1.7}[/tex]

[tex]Z = -1.76[/tex]

[tex]Z = -1.76[/tex] has a pvalue of 0.0392.

Then

P(X < 30) = 0.0392.

b) P(28 < X < 32)

This is the pvalue of Z when X = 32 subtracted by the pvalue of Z when X = 28. So

X = 32

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]Z = \frac{32 - 33}{1.7}[/tex]

[tex]Z = -0.59[/tex]

[tex]Z = -0.59[/tex] has a pvalue of 0.2776.

X = 28

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]Z = \frac{28 - 33}{1.7}[/tex]

[tex]Z = -2.94[/tex]

[tex]Z = -2.94[/tex] has a pvalue of 0.0016.

0.2776 - 0.0016 = 0.2760.

So

P(28 < X < 32) = 0.2760

c) P(X>35)

This is 1 subtracted by the pvalue of Z when X = 35. So

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]Z = \frac{35 - 33}{1.7}[/tex]

[tex]Z = 1.18[/tex]

[tex]Z = 1.18[/tex] has a pvalue of 0.8810.

1 - 0.8810 = 0.1190

So

P(X > 35) = 0.1190

d. P(X>31)

This is 1 subtracted by the pvalue of Z when X = 31. So

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]Z = \frac{31 - 33}{1.7}[/tex]

[tex]Z = -1.18[/tex]

[tex]Z = -1.18[/tex] has a pvalue of 0.1190.

1 - 0.1190 = 0.8810

So

P(X > 31) = 0.8810

e. the mileage rating that the upper 5% of cars achieve.

At least the 95th percentile.

The 95th percentile is X when Z has a pvalue of 0.95. So it is X when Z = 1.645. Then

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]1.645 = \frac{X - 33}{1.7}[/tex]

[tex]X - 33 = 1.645*1.7[/tex]

[tex]X = 35.7965[/tex]

At least 35.7965 mpg

Answer 2

The upper 5% of cars have a mileage rating of 35.805 mpg

What is z score?

Z score is used to determine by how many standard deviations the raw score is above or below the mean. It is given by:

z = (raw score - mean) / standard deviation

Given;  mean of 33 mpg and a standard deviation of 1.7

a) For < 30:

z = (30 - 33)/1.7 = -1.76

P(x < 30) = P(z < -1.76) = 1 - 0.8413 = 0.0392

b) For < 28:

z = (28 - 33)/1.7 = -2.94

P(x < 28) = P(z < -2.94) = 0.0016

c) For > 35:

z = (35 - 33)/1.7 = 1.18

P(x > 35) = P(z > 1.18) = 1 - P(z < 1.18) = 1 - 0.8810 = 0.119

d) For > 31:

z = (31 - 33)/1.7 = -1.18

P(x > 31) = P(z > -1.18) = 1 - P(z < -1.18) = 0.8810

e) The  upper 5% of cars achieve have a z score of 1.65, hence:

1.65 = (x - 33)/1.7

x = 35.805 mpg

The upper 5% of cars have a mileage rating of 35.805 mpg

Find out more on z score at: https://brainly.com/question/25638875


Related Questions

Solve the two-step equation.
-9x + 0.4 = 4
Which operation must be performed to move all the constants to the right side of the equation?

Answers

Answer:

x = -0.4

multi-step equation

Step-by-step explanation:

subtract 0.4 from 4 and 0.4 so it cancells out,

0.4 - 0.4 = 0 (cancelled out)

4 - 0.4 = 3.6

then bring down -9x and divide -9 from both sides

-9/-9 = 0 (cancelled out)

3.6 / -9 = -0.4

x = -0.4

Answer:

x = -0.4

Step-by-step explanation:

We have the equation:

-9x + 0.4 = 4

First, the operation to move all the constants to the right side is subtraction since we would have to subtract 0.4 from each side, let's see this:

Now, we have all the constants on the right side of the equation.

Now, the operation we need to perform to isolate the variable is division (since the x has a -9 that is being multiplied by x) we need to do the opposite operation:

Thus, the answer to this equation is x= -0.4

2. Students who wish to represent the school at a school board meeting are asked to stop

by the office after lunch. After lunch, 5 students wish to represent the school.

Answers

Answer: Biased sample

Step-by-step explanation:

This is a biased sample because only students with strong opinions are likely going to volunteer or show interest in representing the school at the board meeting. This sample is a voluntary type sample, and at such the conclusion is not valid. This sample is biased because a group or population of students have a higher or lower sampling probability.

What’s the correct answer for this question?

Answers

Answer:

A.

Step-by-step explanation:

Volume of sphere = (4/3)πr³

= 4/3(3.14)(d/2)³

= 4/3(3.14)(7/2)³

= 4/3(3.14)(3.5)³

= 4/3(3.14)(42.875)

= (1.33)(3.14)(42.875)

= 179.5 cm³

Answer:

The answer is 179.5 cm^2

If g(x) = 2x - 4), find the value of xf g(x) = 20. 12 points)​

Answers

Answer:

x = 12

Step-by-step explanation:

g(x)= 2x-4

g(x)= 20

Therefore,

2x-4 = 20

Bringing -4 to the other side it becomes positive,so..

2x= 20+4

= 24

x =24/2

= 12

2. {5.0A.A.1, 5.0A.A.2} Write an expression to show....the product of eight
and two, minus the product of three and four. *​

Answers

Answer:

[tex]\left ( 8\times 2 \right )-\left ( 3\times 4 \right )[/tex]

Step-by-step explanation:

Given: The statement is ' the product of eight  and two, minus the product of three and four'

To find: expression for the given statement

Solution:

An algebraic expression is an expression consists of coefficients, variables, and the arithmetic operations.

Product of eight  and two = [tex]\left ( 8\times 2 \right )[/tex]

Product of three and four = [tex]\left ( 3\times 4 \right )[/tex]

Therefore,

Product of eight  and two, minus the product of three and four = [tex]\left ( 8\times 2 \right )-\left ( 3\times 4 \right )[/tex]

A woman forgot her bank ATM PIN but she was able to recall some of the pin.
1)the 1st digit is half of the 2nd pin
2)the sum of 2nd and 3rd is equal to 10
3)the 4th is equal to the 2nd plus 1
4)the sum of all digits is 23
show workings please
what is the ATM digit?

Answers

The PIN is 4829

Step-by-step explanation:

let s take 4 numbers a b c and d

the PIN is abcd

we know that

(1) a = b/2

(2) b+c=10

(3) d=b+1

(4) a+b+c+d=23

from (2) c = 10 - b

from (3) d = b + 1

so (4) gives

b/2 + b + 10 - b + b +1 = 23

so

3/2 b = 23 -11 = 12

b = 12*2/3 = 8

so d = 9

c = 10-8=2

and a = 4

so the PIN is 4829

thank you

Ares is making 14 jars of honey peanut butter. He wants to use 45 milliliter (ML) of honey in each jar. How much honey (in ML) will ares use in all?

Answers

Answer:

630 milliliters.

Step-by-step explanation:

The statement tells us that the final product is 14 jars of honey peanut butter and that in each jar use 45 mliliters of honey. This means that to know the total honey to be used, the required quantity for each jar must be multiplied by the total number of jars, that is:

14 * 45 = 630

Which means that he would spend a total of 630 milliliters.

Step-by-step explanation:

Ares uses 630 ml of honey, because 14×45=630

convert 6 kilograms to grams

Answers

Answer:

6000 grams the formula would be multiply the mass value by 1000

Step-by-step explanation:

Answer:

6000 grams

Step-by-step explanation:

6 kilograms

To convert kg into grams, we multiply by 1000

So,

=> 6 * 1000 grams

=> 6000 grams

Change the fraction1/5 to a percent

Answers

Answer:

Step-by-step explanation:

Help me which answer is it

Answers

Answer:

C.

Step-by-step explanation:

[tex]\frac{1}{5} +\frac{5}{6}[/tex] ≈ 1

5 + 8 + 1 = 14

Aakash has a liability of 6000 due in four years. This liability will be met with payments of A in two years and B in six years. Aakash is employing a full immunization strategy using an annual effective interest rate of 5%.Calculate |A-B|

Answers

Answer:

|A-B|= 586.411565

Step-by-step explanation:

  We know that = Liability

[tex]PLiability= \frac{6000}{1.05^{4} }[/tex]

[tex]\frac{6000}{1.05^{4} }=\frac{A}{1.05^{2} }+\frac{B}{1.05^{6} }\\\\6000(1.05^{2} ) = (1.05^{4} ) +B\\B= 6000(1.05^{2} )-(1.05^{4} )----------(1)\\\\[/tex]

dAssets =dLiability

[tex]4=2*\frac{\frac{A}{1.05^2} }{\frac{6000}{1.05^4} } +6*\frac{\frac{B}{1.05^6} }{\frac{6000}{1.05^4} } \\4={\frac{6000}{1.05^4}= 2*\frac{A}{1.05^2} +6*\frac{B}{1.05^6}\\\\4[6000(1.05^2)]= 2*A(1.05^4)+6*B[/tex]

From equation 1 we have

[tex]4[6000(1.05^2)]= 2*A(1.05^4)+6*6000(1.05^2)-6*A(1.05^4)\\4*A(1.05^4)=2*6000(1.05^2)\\A=\frac{2*6000(1.05^2)}{4*(1.05^4)} \\A=272.088435\\[/tex]

Going back to equation 1 we have

[tex]B= 6000(1.05^2)-A(1.05^4)\\B= 3307.5\\|A-B|= |2721.088435-3307.5|= 586.411565[/tex]

Hitchhiker Snails A type of small snail is very widespread in Japan, and colonies of the snails that are genetically similar have been found very far apart. Scientists wondered how the snails could travel such long distances. A recent study1 provides the answer. Biologist Shinichiro Wada fed live snails to birds and found that of the snails were excreted live out the other end. The snails apparently are able to seal their shells shut to keep the digestive fluids from getting in.
What is the best estimate for the proportion of all snails of this type to live after being eaten by a bird?

Answers

Answer: 0.149

Step-by-step explanation:

As Scientists wondered how the snails could travel such long distances. A recent study provides the answer. Biologist Shinichiro Wada fed 174 live snails to birds and found that 26 of the snails were excreted live out the other end.

The best estimate for the proportion of all snails of this type to live after being eaten by a bird can be achieved by calculating the ratio of survival/number of eaten snails

Where the number of eaten snails = 174

The number of survivors = 26

Estimated proportion = 26/174 = 0.1494

Therefore, the best estimate for the proportion of all snails of this type to live after being eaten by a bird will be 0.149 approximately.

What’s the correct answer for this?

Answers

Answer:

The capital B refers to the base of the area

Step-by-step explanation:

Answer:

A

Step-by-step explanation:

The capital B means the area of the base

An insurance policy pays a total medical benefit consisting of two parts for each claim. Let X represent the part of the benefit that is paid to the surgeon, and let Y represent the part that is paid to the hospital. The variance of X is 5000, the variance of Y is 10,000, and the variance of the total benefit, X + Y, is 17,000. Due to increasing medical costs, the company that issues the policy decides to increase X by a flat amount of 100 per claim and to increase Y by 10% per claim. Calculate the variance of the total benefit after these revisions have been made

Answers

Answer:

= 19300

Step-by-step explanation:

Each claim consists of two parts = X + Y

where

X = the benefit that is paid to the surgeon and

Y = benefit that is paid to the hospital

V(X) = 5000, V(Y) = 10000 and V(X+Y) = 17000

So V(X+Y) = V(X) + V(Y) + 2cov(X,Y)

17000 = 5000 + 10000 +2 cov(X,Y)

17000 -15000 = 2cov(X,Y)

2000 = 2cov(X,Y)

cov(X,Y) = 1000

Now X is increased by flat Rs. 100 per claim and Y by 10% per claim

total benefit = X+100+Y+0.1Y = X+100 + 1.1Y

V(total benefit) = V(X) + 1.1²V(Y) +2(1.1)cov(X,Y) [ V(aX+bY)

= a²V(X) +b²V(Y) +2abcov(X,Y) and V(X+c) = V(X)]

= 5000 + (1.21*10000) + (2.2*1000)

= 5000 + 12100 + 2200

= 19300

I wanted to compare my 5 hamsters’ average intelligence to see if they are different from the average intelligence of the 6 hamsters of another faculty member at a different university. Assume α = .01, then the cutoff for my hypothesis testing is ______.

Answers

Answer:

Step-by-step explanation:

The test to use is the t-test of independent means.

To determine the cutoff for the study then you need to find the degree of freedom and the alpha level. After the hypothesis testing, the calculated t value is then compared to the critical t value from the t distribution table using the degrees of freedom.

What’s the correct answer for this?

Answers

Answer:

(2,-2)

Step-by-step explanation:

In the attached file

Write the value of the digit 5 in this number:178.25
I​

Answers

Step-by-step explanation:

178.25

The number 5 is in the place of one's so the value of 5 is 5

WILL GIVE BRAINLIEST 4 FIRST ANSWER.
When converted to speeds, which list is in order from slowest to fastest?

A: 17 miles in 2 minutes;
26 miles in 4 minutes;
33 miles in 6 minutes;
60 miles in 8 minutes

B: 17 miles in 2 minutes;
60 miles in 8 minutes;
26 miles in 4 minutes;
33 miles in 6 minutes

C: 33 miles in 6 minutes;
26 miles in 4 minutes;
60 miles in 8 minutes;
17 miles in 2 minutes

D: 60 miles in 8 minutes;
33 miles in 6 minutes;
26 miles in 4 minutes;
17 miles in 2 minutes

Answers

Answer:

c

Step-by-step explanation:

you should divide the distance on time

so

33/6=5.5

26/4=6.5

60/8=7.5

17/2=8.5

you can see answer in this order in c

Answer:

Answer:

c

Step-by-step explanation:

you should divide the distance on time

so

33/6=5.5

26/4=6.5

60/8=7.5

17/2=8.5

you can see answer in this order in c

Step-by-step explanation:

Express the following ratio in it’s simplest form.
25:30

Answers

Answer:

5/6

Step-by-step explanation:

Find the factor that divides both numbers...

25/5=5

30/5=6

5/6 is the simplified ratio

P.S. Please give me brainliest, i have only have two!

Answer:

1/3:1/4

Step-by-step explanation:

203/259

write in simplest form

2 hours to 45 seconds

Express ratio

15:1

simplest form

1/3:1/4

f(x)=x^3+10x^2-25x-250

Answers

Answer:

-16x^5

Step-by-step explanation:

f(x)=x^3+10x^2-25x-250

f(x) = x^3-15x+x^2-250

f(x) = x^5-15x-250

f(x) = x^5 -x + 16

f(x) = -x^5+16

f(x) = -16x^5

// have a great day //

2 Points
Which is a kingdom?
O A. Prokarya
B. Protista
C. Mammalia
O D. Chordata​

Answers

Answer:

Protista

Step-by-step explanation:

Archaebacteria.

Eubacteria.

Protista.

Fungi.

Plantae.

Animalia.

These are the 6 kingdoms

A teacher wrote the equation 3y + 12 = 6x on the board. For what value of b would the additional equation 2y = 4x + b form a system of linear equations with infinitely many solutions?
b = –8
b = –4
b = 2
b = 6

Answers

Answer:

-8

Step-by-step explanation:

For a system to have infinitely many solutions the two equations must be the same line. We can simplify the first and second equations by dividing them by 3 and 2 respectively to get:

y + 4 = 2x

y = 2x + b/2 → y -b/2 = 2x

Since the constants must be equal, 4 = -b/2 which means b = -8.

Answer:

b=-8

Step-by-step explanation:

Factorize (3x-2y)2 + 3(3x-2y)-10

Answers

Answer:

[tex]5(3x-2y-2)[/tex] i think. i am sorry if i am wrong

Step-by-step explanation:

pls help it due tomorrow​

Answers

Answer:

Finding 1/5 of something is the same as dividing that number by 5. Since 24 isn't divisible by 5, 24 / 5 is not an integer. Since you can't have 4.8 species of animals the answer to (a) is no.

For (b), 1/3 * 24 = 8 and 24 - 8 = 16.

URGERNT!!!PLS AT LEAST TAKE A LOOK!!! SHARE YO SMARTNESSS!! AND BLESS YOUR GRADES!

Which sign explains the relationship between m∠1 and m∠2 in the diagram?
A) not equal to
B) >
C) <
D) =

Answers

Answer:

Dear Laura Ramirez

Answer to your query is provided below

Option D is correct.

Reason - Because of Hinge and Converse of Hinge theorem

What is an equation of a line, in point-slope form, that
passes through (1, – 7) and has a slope of -2/3

y-7= }(1-1)
y+7= (1+1)
y-7=-|(+1)
y+7=-3(2-1)

Answers

Answer:

y + 7 = -2/3 (x - 1)

Step-by-step explanation:

Point-slope form is y - y1 = m (x - x1)

-7 is y1, -2/3 is m, and 1 is x1

When you plug the values in, you get y + 7 = -2/3 (x - 1)

What is the result of converting 81 inches to feet ? Remember, there are 12 inches in a foot.

A) 69 feet
B) 8.1 feet
C) 7.25 feet
D) 6.75 feet

Answers

Answer:

6.75 ft

Step-by-step explanation:

81 inches

We know there are 12 inches in 1 ft

81 inches * 1 ft/ 12 inches = 81/12 ft =6.75 ft

For a​ long-distance person-to-person telephone​ call, a telephone company charges $ 0.72 for the first​ minute, $ 0.42 for each additional​ minute, and a $ 1.85 service charge. If the cost of a call is $ 8.03 comma how long did the person​ talk?

Answers

Answer:

13 mins

Step-by-step explanation:

8.03- 1.85= 6.18

-.72=5.46

/.42=13

The top and bottom margins of a poster are each 15 cm and the side margins are each 10 cm. If the area of printed material on the poster is fixed at 2400 cm2, find the dimensions of the poster with the smallest area.

Answers

Answer:

the dimension of the poster = 90 cm length and 60 cm  width i.e 90 cm by 60 cm.

Step-by-step explanation:

From the given question.

Let p be the length of the of the printed material

Let q be the width of the of the printed material

Therefore pq = 2400 cm ²

q = [tex]\dfrac{2400 \ cm^2}{p}[/tex]

To find the dimensions of the poster; we have:

the length of the poster to be p+30 and the width to be [tex]\dfrac{2400 \ cm^2}{p} + 20[/tex]

The area of the printed material can now be:  [tex]A = (p+30)(\dfrac{2400 }{p} + 20)[/tex]

=[tex]2400 +20 p +\dfrac{72000}{p}+600[/tex]

Let differentiate with respect to p; we have

[tex]\dfrac{dA}{dp}= 20 - \dfrac{72000}{p^3}[/tex]

Also;

[tex]\dfrac{d^2A}{dp^2}= \dfrac{144000}{p^3}[/tex]

For the smallest area [tex]\dfrac{dA}{dp }=0[/tex]

[tex]20 - \dfrac{72000}{p^2}=0[/tex]

[tex]p^2 = \dfrac{72000}{20}[/tex]

p² = 3600

p =√3600

p = 60

Since p = 60 ; replace p = 60 in the expression  q = [tex]\dfrac{2400 \ cm^2}{p}[/tex]   to solve for q;

q = [tex]\dfrac{2400 \ cm^2}{p}[/tex]

q = [tex]\dfrac{2400 \ cm^2}{60}[/tex]

q = 40

Thus; the printed material has the length of 60 cm and the width of 40cm

the length of the poster = p+30 = 60 +30 = 90 cm

the width of the poster = [tex]\dfrac{2400 \ cm^2}{p} + 20[/tex] = [tex]\dfrac{2400 \ cm^2}{60} + 20[/tex]  = 40 + 20 = 60

Hence; the dimension of the poster = 90 cm length and 60 cm  width i.e 90 cm by 60 cm.

Which of the following sets would have a graph with an open circle on 5 and a ray pointing right on the number line?

Answers

Answer: Choice C  [tex]\{x | x \in \mathbb{R}, \ x > 5 \}[/tex]

The open circle means we do not include the endpoint, hence the use of a greater than symbol. If we were to include the endpoint, then we'd have greater than or equal to. We can rule out choice B due to this reasoning.

The ray pointing to the right indicates we are talking about x values larger than 5, so we can rule out choice A and conclude the answer is C.

Side note: The notation [tex]x \in \mathbb{R}[/tex] is saying "x is a real number"

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