Question 1

Decreasing the sample size causes the sampling distribution of ẍ to ___.

Accepted Answer

A)  shift to the right 
B)  shift to the left 
C)  have more dispersion 
D)  have less dispersion 
E)  stay unchanged 
A)  shift to the right 
B)  shift to the left 
C)  have more dispersion 
D)  have less dispersion 
E)  stay unchanged

Question 2

Let x be a binomial random variable with n = 35 and π =.20. If we use the normal distribution to approximate probabilities for this, we would use a mean of ___.

Accepted Answer

A)  35 
B)  20 
C)  70 
D)  7 
E)  3.5 
A)  35 
B)  20 
C)  70 
D)  7 
E)  3.5

Question 3

Suppose 40% of all college students have a computer at home and a sample of 100 is taken. What is the probability that more than 50 of those in the sample have a computer at home?

Accepted Answer

A)  0.4793 
B)  0.9793 
C)  0.0207 
D)  0.5207 
E)  0.6754 
A)  0.4793 
B)  0.9793 
C)  0.0207 
D)  0.5207 
E)  0.6754

Question 4

According to the central limit theorem, for samples of size 169 drawn from a population with $\mu$ = 1,014 and $\sigma$ = 65, the standard deviation of the sampling distribution of sample means would equal ___.

Accepted Answer

A)  1,014 
B)  65 
C)  15 
D)  6 
E)  5 
A)  1,014 
B)  65 
C)  15 
D)  6 
E)  5

Question 5

According to the central limit theorem, if a sample of size 100 is drawn from a population with a standard deviation of 80, the standard deviation of sample means would equal ___.

Accepted Answer

A)  0.80 
B)  8 
C)  80 
D)  800 
E)  0.080 
A)  0.80 
B)  8 
C)  80 
D)  800 
E)  0.080

Question 6

According to the central limit theorem, if a sample of size 56 is drawn from a population with a mean of 16, the mean of all sample means would equal ___.

Accepted Answer

A)  56 
B)  16 
C)  7.5 
D)  44.0 
E)  196 
A)  56 
B)  16 
C)  7.5 
D)  44.0 
E)  196

Question 7

The normal approximation for binomial distribution can be used when n = 10 and π =1/5.

Accepted Answer

A) True 
 B)False

Question 8

Suppose 30% of the population has green eyes. If a random sample of size 1200 is drawn, then the probability that less than 348 U.S. citizens have green eyes is ___.

Accepted Answer

A)  0.2236 
B)  0.2764 
C)  0.2900 
D)  0.7764 
E)  0.3336 
A)  0.2236 
B)  0.2764 
C)  0.2900 
D)  0.7764 
E)  0.3336

Question 9

Suppose 65% of all college students have a laptop computer at home and a sample of 150 is taken. The standard deviation of the sampling distribution of   is

Accepted Answer

A)  0.0015. 
B)  0.0389. 
C)  0.6500. 
D)  0.4769. 
E)  0.0477. 
A)  0.0015. 
B)  0.0389. 
C)  0.6500. 
D)  0.4769. 
E)  0.0477.

Question 10

According to the central limit theorem, if a sample of size 100 is drawn from a population with a mean of 80, the mean of all sample means would equal ___.

Accepted Answer

A)  0.80 
B)  8 
C)  80 
D)  100 
E)  120 
A)  0.80 
B)  8 
C)  80 
D)  100 
E)  120

Question 11

The employees in certain division of Cybertronics Inc. need to complete a certification online. On average, it takes 20 hours to complete the coursework and successfully pass all tests, and the standard deviation is 6 hours. If you select a random sample of size 30, the probability that the employees in your sample have taken, on average, more than 20.5 hours is ___.

Accepted Answer

A)  0.47 
B)  0.45 
C)  0.41 
D)  0.32 
E)  0.01 
A)  0.47 
B)  0.45 
C)  0.41 
D)  0.32 
E)  0.01

Question 12

The probability that a call to an emergency help line is answered in less than 10 seconds is 0.8. Assume that the calls are independent of each other. Using the normal approximation for binomial with a correction for continuity, the probability that at least 75 of 100 calls are answered within 10 seconds is approximately ___.

Accepted Answer

A)  0.8 
B)  0.1313 
C)  0.5235 
D)  0.9154 
E)  0.8687 
A)  0.8 
B)  0.1313 
C)  0.5235 
D)  0.9154 
E)  0.8687

Question 13

Suppose 90% of students in some specific college have a computer at home and a sample of 40 students is taken. The probability that more than 30 of those in the sample have a computer at home can be approximated using the normal approximation.

Accepted Answer

A) True 
 B)False

Question 14

A random sample of size 100 is drawn from a population with a standard deviation of 10. If only 5% of the time a sample mean greater than 20 is obtained, the mean of the population is ___.

Accepted Answer

A)  18.35 
B)  16.25 
C)  17.2 
D)  20 
E)  19 
A)  18.35 
B)  16.25 
C)  17.2 
D)  20 
E)  19

Question 15

Albert Abbasi, VP of Operations at Ingleside International Bank, is evaluating the service level provided to walk-in customers. Accordingly, he plans a sample of waiting times for walk-in customers. If the population of waiting times has a mean of 15 minutes and a standard deviation of 4 minutes, the probability that Albert's sample of 64 will have a mean less than 16 minutes is ___.

Accepted Answer

A)  0.4772 
B)  0.0228 
C)  0.9072 
D)  0.9544 
E)  0.9772 
A)  0.4772 
B)  0.0228 
C)  0.9072 
D)  0.9544 
E)  0.9772

Question 16

Pinky Bauer, Chief Financial Officer of Harrison Haulers, Inc., suspects irregularities in the payroll system. If 10% of the 5,000 payroll vouchers issued since January 1, 2000, have irregularities, the probability that Pinky's random sample of 200 vouchers will have a sample proportion of between.06 and.14 is ___.

Accepted Answer

A)  0.4706 
B)  0.9706 
C)  0.0588 
D)  0.9412 
E)  0.8765 
A)  0.4706 
B)  0.9706 
C)  0.0588 
D)  0.9412 
E)  0.8765

Question 17

Suppose the population of all colleges shows the annual parking fee per student is $110 with a standard deviation of $18. If a random sample of size 49 is drawn from the population, the probability of drawing a sample with a sample mean between $112 and $115 is ___.

Accepted Answer

A)  0.9738 
B)  0.7777 
C)  0.7823 
D)  0.1915 
E)  1.7561 
A)  0.9738 
B)  0.7777 
C)  0.7823 
D)  0.1915 
E)  1.7561

Question 18

Assuming an equal chance of a new baby being a boy or a girl (that is, π = 0.5), we would like to find the probability of 40 or more of the next 100 births at a local hospital will be boys. Using the normal approximation for binomial with a correction for continuity, we should use the z score ___.

Accepted Answer

A)  0.4 
B)  -2.1 
C)  0.6 
D)  2 
E)  -1.7 
A)  0.4 
B)  -2.1 
C)  0.6 
D)  2 
E)  -1.7

Question 19

Catherine Chao, Director of Marketing Research, needs a sample of Kansas City households to participate in the testing of a new toothpaste package. If 40% of the households in Kansas City prefer the new package, the probability that Catherine's random sample of 300 households will have a sample proportion greater than 0.45 is ___.

Accepted Answer

A)  0.9232 
B)  0.0768 
C)  0.4616 
D)  0.0384 
E)  0.8974 
A)  0.9232 
B)  0.0768 
C)  0.4616 
D)  0.0384 
E)  0.8974

Question 20

Suppose 40% of the population of pre-teens have a TV in their bedroom. If a random sample of 500 pre-teens is drawn from the population, then the probability that between 36% and 44% of the pre-teens have a TV in their bedroom is ___.

Accepted Answer

A)  0.9644 
B)  0.4644 
C)  0.0356 
D)  0.9328 
E)  0.0712 
A)  0.9644 
B)  0.4644 
C)  0.0356 
D)  0.9328 
E)  0.0712

Decreasing the sample size causes the sampling distribution of ẍ to ___.

Let x be a binomial random variable with n = 35 and π =.20. If we use the normal distribution to approximate probabilities for this, we would use a mean of ___.

Suppose 40% of all college students have a computer at home and a sample of 100 is taken. What is the probability that more than 50 of those in the sample have a computer at home?

According to the central limit theorem, for samples of size 169 drawn from a population with $\mu$ = 1,014 and $\sigma$ = 65, the standard deviation of the sampling distribution of sample means would equal ___.

According to the central limit theorem, if a sample of size 100 is drawn from a population with a standard deviation of 80, the standard deviation of sample means would equal ___.

According to the central limit theorem, if a sample of size 56 is drawn from a population with a mean of 16, the mean of all sample means would equal ___.

The normal approximation for binomial distribution can be used when n = 10 and π =1/5.

Suppose 30% of the population has green eyes. If a random sample of size 1200 is drawn, then the probability that less than 348 U.S. citizens have green eyes is ___.

Suppose 65% of all college students have a laptop computer at home and a sample of 150 is taken. The standard deviation of the sampling distribution of is

According to the central limit theorem, if a sample of size 100 is drawn from a population with a mean of 80, the mean of all sample means would equal ___.

Suppose 90% of students in some specific college have a computer at home and a sample of 40 students is taken. The probability that more than 30 of those in the sample have a computer at home can be approximated using the normal approximation.

A random sample of size 100 is drawn from a population with a standard deviation of 10. If only 5% of the time a sample mean greater than 20 is obtained, the mean of the population is ___.

Suppose the population of all colleges shows the annual parking fee per student is $110 with a standard deviation of $18. If a random sample of size 49 is drawn from the population, the probability of drawing a sample with a sample mean between $112 and $115 is ___.

Assuming an equal chance of a new baby being a boy or a girl (that is, π = 0.5), we would like to find the probability of 40 or more of the next 100 births at a local hospital will be boys. Using the normal approximation for binomial with a correction for continuity, we should use the z score ___.

Suppose 40% of the population of pre-teens have a TV in their bedroom. If a random sample of 500 pre-teens is drawn from the population, then the probability that between 36% and 44% of the pre-teens have a TV in their bedroom is ___.

Introduction to Statistics

Organizing and Visualizing Data

Descriptive Statistics

Gathering Data

Probability

Decision Analysis and Expected Value

Discrete Probability Distributions

Continuous Distributions

Confidence Intervals

Hypothesis Testing for Single Populations

Hypothesis Testing for Two Populations

Analysis of Variance Anova

Linear Correlation and Simple Linear Regression Analysis

Categorical Versus Categorical: Tests

Filters

Exam 9: Sampling Distributions

Decreasing the sample size causes the sampling distribution of ẍ to ___.

Let x be a binomial random variable with n = 35 and π =.20. If we use the normal distribution to approximate probabilities for this, we would use a mean of ___.

Suppose 40% of all college students have a computer at home and a sample of 100 is taken. What is the probability that more than 50 of those in the sample have a computer at home?

According to the central limit theorem, for samples of size 169 drawn from a population with μ\muμ = 1,014 and σ\sigmaσ = 65, the standard deviation of the sampling distribution of sample means would equal ___.

According to the central limit theorem, if a sample of size 100 is drawn from a population with a standard deviation of 80, the standard deviation of sample means would equal ___.

According to the central limit theorem, if a sample of size 56 is drawn from a population with a mean of 16, the mean of all sample means would equal ___.

The normal approximation for binomial distribution can be used when n = 10 and π =1/5.

Suppose 30% of the population has green eyes. If a random sample of size 1200 is drawn, then the probability that less than 348 U.S. citizens have green eyes is ___.

Suppose 65% of all college students have a laptop computer at home and a sample of 150 is taken. The standard deviation of the sampling distribution of is

According to the central limit theorem, if a sample of size 100 is drawn from a population with a mean of 80, the mean of all sample means would equal ___.

Suppose 90% of students in some specific college have a computer at home and a sample of 40 students is taken. The probability that more than 30 of those in the sample have a computer at home can be approximated using the normal approximation.

A random sample of size 100 is drawn from a population with a standard deviation of 10. If only 5% of the time a sample mean greater than 20 is obtained, the mean of the population is ___.

Suppose the population of all colleges shows the annual parking fee per student is $110 with a standard deviation of $18. If a random sample of size 49 is drawn from the population, the probability of drawing a sample with a sample mean between $112 and $115 is ___.

Assuming an equal chance of a new baby being a boy or a girl (that is, π = 0.5), we would like to find the probability of 40 or more of the next 100 births at a local hospital will be boys. Using the normal approximation for binomial with a correction for continuity, we should use the z score ___.

Suppose 40% of the population of pre-teens have a TV in their bedroom. If a random sample of 500 pre-teens is drawn from the population, then the probability that between 36% and 44% of the pre-teens have a TV in their bedroom is ___.

Introduction to Statistics

Organizing and Visualizing Data

Descriptive Statistics

Gathering Data

Probability

Decision Analysis and Expected Value

Discrete Probability Distributions

Continuous Distributions

Confidence Intervals

Hypothesis Testing for Single Populations

Hypothesis Testing for Two Populations

Analysis of Variance Anova

Linear Correlation and Simple Linear Regression Analysis

Categorical Versus Categorical: Tests

Filters

According to the central limit theorem, for samples of size 169 drawn from a population with $\mu$ = 1,014 and $\sigma$ = 65, the standard deviation of the sampling distribution of sample means would equal ___.