Question 1

Identify the probability of each sample, and describe the sampling distribution of the sample means.
-The number of books sold over the course of the four-day book fair were 189, 167, 271, and 83. Assume that samples of size 2 are randomly selected with replacement from this population of four values.

Accepted Answer

A)    1/16;1/8;0/16;1/16;1/8;0/16;1/16;1/8;0/16;1/16;1/8;0/16;1/16;1/8;0/16;1/161 / 16 ; 1 / 8 ; 0 / 16 ; 1 / 16 ; 1 / 8 ; 0 / 16 ; 1 / 16 ; 1 / 8 ; 0 / 16 ; 1 / 16 ; 1 / 8 ; 0 / 16 ; 1 / 16 ; 1 / 8 ; 0 / 16 ; 1 / 161/16;1/8;0/16;1/16;1/8;0/16;1/16;1/8;0/16;1/16;1/8;0/16;1/16;1/8;0/16;1/16 
B)    1/16;1/16;1/16;1/16;1/16;1/16;1/16;1/16;1/16;1/16;1/16;1/16;1/16;1/16;1/16;1/161 / 16 ; 1 / 16 ; 1 / 16 ; 1 / 16 ; 1 / 16 ; 1 / 16 ; 1 / 16 ; 1 / 16 ; 1 / 16 ; 1 / 16 ; 1 / 16 ; 1 / 16 ; 1 / 16 ; 1 / 16 ; 1 / 16 ; 1 / 161/16;1/16;1/16;1/16;1/16;1/16;1/16;1/16;1/16;1/16;1/16;1/16;1/16;1/16;1/16;1/16 
C)    1/2;1/16;1/4;1/16;1/4;1/16;1/2;1/16;1/4;1/16;1/2;1/16;1/4;1/16;1/2;1/161 / 2 ; 1 / 16 ; 1 / 4 ; 1 / 16 ; 1 / 4 ; 1 / 16 ; 1 / 2 ; 1 / 16 ; 1 / 4 ; 1 / 16 ; 1 / 2 ; 1 / 16 ; 1 / 4 ; 1 / 16 ; 1 / 2 ; 1 / 161/2;1/16;1/4;1/16;1/4;1/16;1/2;1/16;1/4;1/16;1/2;1/16;1/4;1/16;1/2;1/16 
D)    0/16;1/16;1/8;0/16;1/16;1/8;1/16;0/16;1/8;1/16;1/16;1/8;1/16;0/16;1/8;1/160 / 16 ; 1 / 16 ; 1 / 8 ; 0 / 16 ; 1 / 16 ; 1 / 8 ; 1 / 16 ; 0 / 16 ; 1 / 8 ; 1 / 16 ; 1 / 16 ; 1 / 8 ; 1 / 16 ; 0 / 16 ; 1 / 8 ; 1 / 160/16;1/16;1/8;0/16;1/16;1/8;1/16;0/16;1/8;1/16;1/16;1/8;1/16;0/16;1/8;1/16E) A) and C)
F) All of the above

Question 2

Solve the problem.
-A final exam in Math 160 has a mean of 73 with standard deviation 7.8. If 24 students are randomly selected, find the probability that the mean of their test scores is less than 70.

Accepted Answer

A)  0.9699
B)  0.0301
C)  0.1006
D)  0.0278E) A) and B)
F) A) and C)

Question 3

Solve the problem.
-A study of the amount of time it takes a mechanic to rebuild the transmission for a 1992 Chevrolet Cavalier shows that the mean is 8.4 hours and the standard deviation is 1.8 hours. If 40 mechanics are randomly selected, find the probability that their mean rebuild time exceeds 8.1 hours.

Accepted Answer

A)  0.8531
B)  0.9146
C)  0.7285
D)  0.8457E) A) and B)
F) C) and D)

Question 4

Provide an appropriate response.
-Sketch a brief diagram of the standard normal distribution table. You only need to show two sets of values. Identify the z scores and the area scores in the table by circling the scores and writing z score and area by each one. Describe how to find the area corresponding to a given z score. Describe how to find the the z score corresponding to a given area value.

Accepted Answer

A quick sketch of a couple of values sho...

Question 5

Solve the problem.
-In one region, the September energy consumption levels for single-family homes are found to be normally distributed with a mean of 1050 kWh and a standard deviation of 218 kWh. If 50 different homes are randomly selected, find the probability that their mean energy consumption level for September is greater than 1075 kWh.

Accepted Answer

A)  0.2090
B)  0.0438
C)  0.2910
D)  0.4562E) A) and D)
F) None of the above

Question 6

For the binomial distribution with the given values for n and p
-n = 12 and p = .5

Accepted Answer

A)  Normal approximation is not suitable.
B)  Normal approximation is suitable.C) A) and B)
D) undefined

Question 7

Find the probability that in 200 tosses of a fair die, we will obtain at most 30 fives.

Accepted Answer

A)  .3229
B)  .2946
C)  .4936
D)  .1871E) A) and B)
F) C) and D)

Question 8

A normal probability plot is given below for a sample of scores on an aptitude test. Use the plot to assess the normality of scores on this test. Explain your reasoning.

Accepted Answer

Since the normal probability p...

Question 9

If Z is a standard normal variable, find the probability
-The probability that Z lies between 0.7 and 1.98

Accepted Answer

A)  1.7341
B)  0.2181
C)  0.2175
D)  -0.2181E) C) and D)
F) B) and D)

Question 10

Construct a normal probability plot of the given data. Use your plot to determine whether the data come from a normally distributed population
-The ages of 30 students selected randomly from one college are as follows: $$\begin{array} { l l l l l } 
21 & 23 & 20 & 24 & 20 \
19 & 20 & 19 & 22 & 32 \
20 & 24 & 26 & 21 & 37 \
23 & 18 & 34 & 25 & 30 \
22 & 24 & 23 & 19 & 28 \
20 & 29 & 21 & 35 & 25 \
20 & 21 & 28 & 22 & 32
\end{array}$$

Accepted Answer

The requirement for normality ...

Question 11

A poll of 1200 randomly selected students in grades 6 through 8 was conducted and found that 39% enjoy playing sports. What is the sampling distribution suggested by the given data?

Accepted Answer

It is the probability distribu...

Question 12

Scores on a test have a mean of 62 and  Q3\mathrm { Q } _ { 3 }Q3​  is 84. The scores have a distribution that is approximately normal. Find the standard deviation. Round your answer to the nearest tenth.

Accepted Answer

A)  14.7
B)  32.8
C)  29.3
D)  16.5 E) A) and C)
F) A) and B)

Question 13

List the different possible samples, and find the mean of each of them
-Personal phone calls received in the last three days by a new employee were 3, 1, and 8. Assume that samples of size 2 are randomly selected with replacement from this population of three values.

Accepted Answer

Possible samples: 3-3; 3-1; 3-...

Question 14

Use the continuity correction and describe the region of the normal curve that corresponds to the indicated binomial probability.
-The probability of fewer than 43 democrats

Accepted Answer

A)  The area to the left of 43
B)  The area to the left of 43.5
C)  The area to the right of 43.5
D)  The area to the left of 42.5E) None of the above
F) All of the above

Question 15

The Precision Scientific Instrument Company manufactures thermometers that are supposed to give readings of 0°C at the freezing point of water. Tests on a large sample of these thermometers reveal that at the freezing point of water, some give readings below 0°C (denoted by negative numbers)  and some give readings above 0°C (denoted by positive numbers) . Assume that the mean reading is 0°C and the standard deviation of the readings is 1.00°C. Also assume that the frequency distribution of errors closely resembles the normal distribution. A thermometer is randomly selected and tested. Find the temperature reading corresponding to the given information.
-P(-0.73 < Z < 2.27)

Accepted Answer

A)  0.4884
B)  0.7557
C)  1.54
D)  0.2211E) None of the above
F) B) and C)

Question 16

Solve the problem.
-In a population of 225 women, the heights of the women are normally distributed with a mean of 64.5 inches and a standard deviation of 2.9 inches. If 25 women are selected at random, find the probability that their mean height will exceed 66 inches. Assume that the sampling is done without replacement and use a finite population correction factor with N = 225.

Accepted Answer

A)  0.3015
B)  0.0048
C)  0.2912
D)  0.0031E) A) and B)
F) A) and C)

Question 17

Use the continuity correction and describe the region of the normal curve that corresponds to the indicated binomial probability.
-The probability of exactly 37 green marbles

Accepted Answer

A)  The area between 36.5 and 37.5
B)  The area between 37 and 37.5
C)  The area between 36.5 and 37
D)  The area between 36.5 and 38.5E) C) and D)
F) A) and D)

Question 18

If Z is a standard normal variable, find the probability
-The probability that Z lies between -0.55 and 0.55

Accepted Answer

A)  -0.9000
B)  -0.4176
C)  0.9000
D)  0.4176E) B) and D)
F) None of the above

Question 19

Solve the problem.
-Assume that  z\mathrm { z }z  scores are normally distributed with a mean of 0 and a standard deviation of 1 . If   \mathrm { c } )  = 0.1093">P(z>c) =0.1093\mathrm { P } ( \mathrm { z } > \mathrm { c } )  = 0.1093P(z>c) =0.1093 , find  c\mathrm { c }c .

Accepted Answer

A)    −1.23- 1.23−1.23 
B)    1.231.231.23 
C)    0.45620.45620.4562 
D)    0.270.270.27E) C) and D)
F) A) and B)

Question 20

Estimate the indicated probability by using the normal distribution as an approximation to the binomial distribution.
-n = 38 and p = .9

Accepted Answer

A)  Normal approximation is suitable.
B)  Normal approximation is not suitable.C) A) and B)
D) undefined

Exam 6: Normal Probability Distributions

Correct Answer
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Estimate the indicated probability by using the normal distribution as an approximation to the binomial distribution. -n = 38 and p = .9

Correct Answer
verified

Correct Answer
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A poll of 1200 randomly selected students in grades 6 through 8 was conducted and found that 39% enjoy playing sports. What is the sampling distribution suggested by the given data?

Correct Answer
verified
It is the probability distribu...
View Answer

Correct Answer
verified
The requirement for normality ...
View Answer

Use the continuity correction and describe the region of the normal curve that corresponds to the indicated binomial probability. -The probability of fewer than 43 democrats

Correct Answer
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If Z is a standard normal variable, find the probability -The probability that Z lies between 0.7 and 1.98

Correct Answer
verified

Use the continuity correction and describe the region of the normal curve that corresponds to the indicated binomial probability. -The probability of exactly 37 green marbles

Correct Answer
verified

Solve the problem. -A final exam in Math 160 has a mean of 73 with standard deviation 7.8. If 24 students are randomly selected, find the probability that the mean of their test scores is less than 70.

Correct Answer
verified

Correct Answer
verified

Find the probability that in 200 tosses of a fair die, we will obtain at most 30 fives.

Correct Answer
verified

A normal probability plot is given below for a sample of scores on an aptitude test. Use the plot to assess the normality of scores on this test. Explain your reasoning.

Correct Answer
verified
Since the normal probability p...
View Answer

For the binomial distribution with the given values for n and p -n = 12 and p = .5

Correct Answer
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Scores on a test have a mean of 62 and $\mathrm { Q } _ { 3 }$ is 84. The scores have a distribution that is approximately normal. Find the standard deviation. Round your answer to the nearest tenth.

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

If Z is a standard normal variable, find the probability -The probability that Z lies between -0.55 and 0.55

Correct Answer
verified

Solve the problem. -Assume that $\mathrm { z }$ scores are normally distributed with a mean of 0 and a standard deviation of 1 . If $\mathrm { P } ( \mathrm { z } > \mathrm { c } ) = 0.1093$ , find $\mathrm { c }$ .

Correct Answer
verified

Correct Answer
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A quick sketch of a couple of values sho...
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List the different possible samples, and find the mean of each of them -Personal phone calls received in the last three days by a new employee were 3, 1, and 8. Assume that samples of size 2 are randomly selected with replacement from this population of three values.

Correct Answer
verified
Possible samples: 3-3; 3-1; 3-...
View Answer

Exam 6: Normal Probability Distributions

Correct AnswerverifiedShow Answer

Estimate the indicated probability by using the normal distribution as an approximation to the binomial distribution. -n = 38 and p = .9

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

A poll of 1200 randomly selected students in grades 6 through 8 was conducted and found that 39% enjoy playing sports. What is the sampling distribution suggested by the given data?

Correct AnswerverifiedIt is the probability distribu...View AnswerShow Answer

Correct AnswerverifiedThe requirement for normality ...View AnswerShow Answer

Use the continuity correction and describe the region of the normal curve that corresponds to the indicated binomial probability. -The probability of fewer than 43 democrats

Correct AnswerverifiedShow Answer

If Z is a standard normal variable, find the probability -The probability that Z lies between 0.7 and 1.98

Correct AnswerverifiedShow Answer

Use the continuity correction and describe the region of the normal curve that corresponds to the indicated binomial probability. -The probability of exactly 37 green marbles

Correct AnswerverifiedShow Answer

Solve the problem. -A final exam in Math 160 has a mean of 73 with standard deviation 7.8. If 24 students are randomly selected, find the probability that the mean of their test scores is less than 70.

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Find the probability that in 200 tosses of a fair die, we will obtain at most 30 fives.

Correct AnswerverifiedShow Answer

A normal probability plot is given below for a sample of scores on an aptitude test. Use the plot to assess the normality of scores on this test. Explain your reasoning.

Correct AnswerverifiedSince the normal probability p...View AnswerShow Answer

For the binomial distribution with the given values for n and p -n = 12 and p = .5

Correct AnswerverifiedShow Answer

Scores on a test have a mean of 62 and Q3\mathrm { Q } _ { 3 }Q3​ is 84. The scores have a distribution that is approximately normal. Find the standard deviation. Round your answer to the nearest tenth.

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Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

If Z is a standard normal variable, find the probability -The probability that Z lies between -0.55 and 0.55

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Solve the problem. -Assume that z\mathrm { z }z scores are normally distributed with a mean of 0 and a standard deviation of 1 . If P(z>c) =0.1093\mathrm { P } ( \mathrm { z } > \mathrm { c } ) = 0.1093P(z>c) =0.1093 , find c\mathrm { c }c .

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Correct AnswerverifiedA quick sketch of a couple of values sho...View AnswerShow Answer

List the different possible samples, and find the mean of each of them -Personal phone calls received in the last three days by a new employee were 3, 1, and 8. Assume that samples of size 2 are randomly selected with replacement from this population of three values.

Correct AnswerverifiedPossible samples: 3-3; 3-1; 3-...View AnswerShow Answer

Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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It is the probability distribu...
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Correct Answer
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The requirement for normality ...
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
verified

Correct Answer
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Correct Answer
verified

Correct Answer
verified
Since the normal probability p...
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Correct Answer
verified

Scores on a test have a mean of 62 and $\mathrm { Q } _ { 3 }$ is 84. The scores have a distribution that is approximately normal. Find the standard deviation. Round your answer to the nearest tenth.

Correct Answer
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Correct Answer
verified

Correct Answer
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Correct Answer
verified

Solve the problem. -Assume that $\mathrm { z }$ scores are normally distributed with a mean of 0 and a standard deviation of 1 . If $\mathrm { P } ( \mathrm { z } > \mathrm { c } ) = 0.1093$ , find $\mathrm { c }$ .

Correct Answer
verified

Correct Answer
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A quick sketch of a couple of values sho...
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Correct Answer
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Possible samples: 3-3; 3-1; 3-...
View Answer