Question 1

Which of the following can be reduced by proper interviewer training?

Accepted Answer

A)  Sampling error 
B)  Measurement error 
C)  Both of the above 
D)  None of the above 
A)  Sampling error 
B)  Measurement error 
C)  Both of the above 
D)  None of the above

Question 2

Suppose the ages of students in Statistics 101 follow a right skewed distribution with a mean of 23 years and a standard deviation of 3 years. If we randomly sampled 100 students, which of the following statements about the sampling distribution of the sample mean age is incorrect?

Accepted Answer

A)  The mean of the sampling distribution is equal to 23 years. 
B)  The standard deviation of the sampling distribution is equal to 3 years. 
C)  The shape of the sampling distribution is approximately normal. 
D)  The standard error of the sampling distribution is equal to 0.3 years. 
A)  The mean of the sampling distribution is equal to 23 years. 
B)  The standard deviation of the sampling distribution is equal to 3 years. 
C)  The shape of the sampling distribution is approximately normal. 
D)  The standard error of the sampling distribution is equal to 0.3 years.

Question 3

The mean of the sampling distribution of a sample proportion is the population proportion, π.

Accepted Answer

A) True 
 B)False

Question 4

The amount of bleach a machine pours into bottles has a mean of 36 oz. with a standard deviation of 0.15 oz. Suppose we take a random sample of 36 bottles filled by this machine. So, the middle 95% of the sample means based on samples of size 36 will be between ________ and ________.

Accepted Answer

35.951; 36

Question 5

Which of the following sampling methods is a probability sample?

Accepted Answer

A)  Convenience sample 
B)  Quota sample 
C)  Stratified sample 
D)  Judgment sample 
A)  Convenience sample 
B)  Quota sample 
C)  Stratified sample 
D)  Judgment sample

Question 6

A sample of 300 subscribers to a particular magazine is selected from a population frame of 9,000 subscribers. If, upon examining the data, it is determined that no subscriber had been selected in the sample more than once,

Accepted Answer

A)  the sample could not have been random. 
B)  the sample may have been selected without replacement or with replacement. 
C)  the sample had to have been selected with replacement. 
D)  the sample had to have been selected without replacement. 
A)  the sample could not have been random. 
B)  the sample may have been selected without replacement or with replacement. 
C)  the sample had to have been selected with replacement. 
D)  the sample had to have been selected without replacement.

Question 7

The amount of bleach a machine pours into bottles has a mean of 36 oz. with a standard deviation of 0.15 oz. Suppose we take a random sample of 36 bottles filled by this machine. The sampling distribution of the sample mean has a mean of 36 oz.

Accepted Answer

A) True 
 B)False

Question 8

The evening host of a dinner dance reached into a bowl, mixed all the tickets around, and selected the ticket to award the grand door prize. What sampling method was used?

Accepted Answer

A)  Simple random sample 
B)  Systematic sample 
C)  Stratified sample 
D)  Cluster sample 
A)  Simple random sample 
B)  Systematic sample 
C)  Stratified sample 
D)  Cluster sample

Question 9

A manufacturer of power tools claims that the mean amount of time required to assemble their top-of-the-line table saw is 80 minutes with a standard deviation of 40 minutes. Suppose a random sample of 64 purchasers of this table saw is taken. The probability that the sample mean will be between 77 and 89 minutes is ________.

Accepted Answer

The answer of A manufacturer of power tools claims that...

Question 10

Which of the following yields a stratified sample?

Accepted Answer

A)  All students in a class are divided into groups of 15. One student is randomly chosen from the 1st group, the remaining observations are every 15th student thereafter. 
B)  The best 15 students, according to the opinion of the instructor, in a class are selected. 
C)  All students in a class are grouped according to their gender. A random sample of 8 is selected from the males and a separate random sample of 7 is drawn from the females. 
D)  The first 15 students in a class are selected without replacement. 
A)  All students in a class are divided into groups of 15. One student is randomly chosen from the 1st group, the remaining observations are every 15th student thereafter. 
B)  The best 15 students, according to the opinion of the instructor, in a class are selected. 
C)  All students in a class are grouped according to their gender. A random sample of 8 is selected from the males and a separate random sample of 7 is drawn from the females. 
D)  The first 15 students in a class are selected without replacement.

Question 11

For air travelers, one of the biggest complaints is of the waiting time between when the airplane taxis away from the terminal until the flight takes off. This waiting time is known to have a right skewed distribution with a mean of 10 minutes and a standard deviation of 8 minutes. Suppose 100 flights have been randomly sampled. Describe the sampling distribution of the mean waiting time between when the airplane taxis away from the terminal until the flight takes off for these 100 flights.

Accepted Answer

A)  Distribution is right skewed with mean = 10 minutes and standard error = 0.8 minutes. 
B)  Distribution is right skewed with mean = 10 minutes and standard error = 8 minutes. 
C)  Distribution is approximately normal with mean = 10 minutes and standard error = 0.8 minutes. 
D)  Distribution is approximately normal with mean = 10 minutes and standard error = 8 minutes. 
A)  Distribution is right skewed with mean = 10 minutes and standard error = 0.8 minutes. 
B)  Distribution is right skewed with mean = 10 minutes and standard error = 8 minutes. 
C)  Distribution is approximately normal with mean = 10 minutes and standard error = 0.8 minutes. 
D)  Distribution is approximately normal with mean = 10 minutes and standard error = 8 minutes.

Question 12

The only reliable way a researcher can make statistical inferences from a sample to a population is to use nonprobability sampling methods.

Accepted Answer

A) True 
 B)False

Question 13

TABLE 7-2
The time spent studying by students in the week before final exams follows a normal distribution with a standard deviation of 8 hours. A random sample of 4 students was taken in order to estimate the mean study time for the population of all students.
-Referring to Table 7-2, what is the probability that the sample mean differs from the population mean by less than 2 hours?

Accepted Answer

0.3829 usi

Question 14

The standard error of the sampling distribution of a sample proportion is where $ \sqrt{\frac{\rho(1-\rho)}{n}} $ ρ is the sample proportion.

Accepted Answer

A) True 
 B)False

Question 15

At a computer manufacturing company, the actual size of computer chips is normally distributed with a mean of 1 centimeter and a standard deviation of 0.1 centimeter. A random sample of 12 computer chips is taken. What is the probability that the sample mean will be below 0.95 centimeters?

Accepted Answer

0.0416 usi

Question 16

If the population distribution is unknown, in most cases the sampling distribution of the mean can be approximated by the normal distribution if the samples contain at least 30 observations.

Accepted Answer

A) True 
 B)False

Question 17

Systematic samples are less efficient than a stratified sample.

Accepted Answer

A) True 
 B)False

Question 18

To estimate the mean number of hours a student at a major university spent in the library, a researcher obtained the list of students from the registrar's office, from which she can select a random sample 200 students. This list is a ________.

Accepted Answer

The answer of To estimate the mean number of hours...

Question 19

The standard error of the population proportion will become larger

Accepted Answer

A)  as population proportion approaches 0. 
B)  as population proportion approaches 0.50. 
C)  as population proportion approaches 1.00. 
D)  as the sample size increases. 
A)  as population proportion approaches 0. 
B)  as population proportion approaches 0.50. 
C)  as population proportion approaches 1.00. 
D)  as the sample size increases.

Question 20

Which of the following is true about the sampling distribution of the sample mean?

Accepted Answer

A)  The mean of the sampling distribution is always μ. 
B)  The standard deviation of the sampling distribution is always σ. 
C)  The shape of the sampling distribution is always approximately normal. 
D)  All of the above are true. 
A)  The mean of the sampling distribution is always μ. 
B)  The standard deviation of the sampling distribution is always σ. 
C)  The shape of the sampling distribution is always approximately normal. 
D)  All of the above are true.

Which of the following can be reduced by proper interviewer training?

Suppose the ages of students in Statistics 101 follow a right skewed distribution with a mean of 23 years and a standard deviation of 3 years. If we randomly sampled 100 students, which of the following statements about the sampling distribution of the sample mean age is incorrect?

The mean of the sampling distribution of a sample proportion is the population proportion, π.

The amount of bleach a machine pours into bottles has a mean of 36 oz. with a standard deviation of 0.15 oz. Suppose we take a random sample of 36 bottles filled by this machine. So, the middle 95% of the sample means based on samples of size 36 will be between and .

Which of the following sampling methods is a probability sample?

A sample of 300 subscribers to a particular magazine is selected from a population frame of 9,000 subscribers. If, upon examining the data, it is determined that no subscriber had been selected in the sample more than once,

The amount of bleach a machine pours into bottles has a mean of 36 oz. with a standard deviation of 0.15 oz. Suppose we take a random sample of 36 bottles filled by this machine. The sampling distribution of the sample mean has a mean of 36 oz.

The evening host of a dinner dance reached into a bowl, mixed all the tickets around, and selected the ticket to award the grand door prize. What sampling method was used?

Which of the following yields a stratified sample?

The only reliable way a researcher can make statistical inferences from a sample to a population is to use nonprobability sampling methods.

The standard error of the sampling distribution of a sample proportion is where $\sqrt{\frac{\rho(1-\rho)}{n}}$ ρ is the sample proportion.

At a computer manufacturing company, the actual size of computer chips is normally distributed with a mean of 1 centimeter and a standard deviation of 0.1 centimeter. A random sample of 12 computer chips is taken. What is the probability that the sample mean will be below 0.95 centimeters?

If the population distribution is unknown, in most cases the sampling distribution of the mean can be approximated by the normal distribution if the samples contain at least 30 observations.

Systematic samples are less efficient than a stratified sample.

To estimate the mean number of hours a student at a major university spent in the library, a researcher obtained the list of students from the registrar's office, from which she can select a random sample 200 students. This list is a ________.

The standard error of the population proportion will become larger

Which of the following is true about the sampling distribution of the sample mean?

Introduction

Organizing and Visualizing Data

Numerical Descriptive Measures

Basic Probability

Discrete Probability Distributions

The Normal Distribution and Other Continuous Distributions

Confidence Interval Estimation

Fundamentals of Hypothesis Testing: One-Sample Tests

Two-Sample Tests

Analysis of Variance

Chi-Square Tests and Nonparametric Tests

Simple Linear Regression

Introduction to Multiple Regression

Multiple Regression Model Building

Time-Series Forecasting

Statistical Applications in Quality Management

A Roadmap for Analyzing Data

Filters

Exam 7: Sampling and Sampling Distributions

Which of the following can be reduced by proper interviewer training?

Suppose the ages of students in Statistics 101 follow a right skewed distribution with a mean of 23 years and a standard deviation of 3 years. If we randomly sampled 100 students, which of the following statements about the sampling distribution of the sample mean age is incorrect?

The mean of the sampling distribution of a sample proportion is the population proportion, π.

The amount of bleach a machine pours into bottles has a mean of 36 oz. with a standard deviation of 0.15 oz. Suppose we take a random sample of 36 bottles filled by this machine. So, the middle 95% of the sample means based on samples of size 36 will be between ________ and ________.

Which of the following sampling methods is a probability sample?

A sample of 300 subscribers to a particular magazine is selected from a population frame of 9,000 subscribers. If, upon examining the data, it is determined that no subscriber had been selected in the sample more than once,

The amount of bleach a machine pours into bottles has a mean of 36 oz. with a standard deviation of 0.15 oz. Suppose we take a random sample of 36 bottles filled by this machine. The sampling distribution of the sample mean has a mean of 36 oz.

The evening host of a dinner dance reached into a bowl, mixed all the tickets around, and selected the ticket to award the grand door prize. What sampling method was used?

Which of the following yields a stratified sample?

The only reliable way a researcher can make statistical inferences from a sample to a population is to use nonprobability sampling methods.

The standard error of the sampling distribution of a sample proportion is where ρ(1−ρ)n \sqrt{\frac{\rho(1-\rho)}{n}} nρ(1−ρ)​​ ρ is the sample proportion.

At a computer manufacturing company, the actual size of computer chips is normally distributed with a mean of 1 centimeter and a standard deviation of 0.1 centimeter. A random sample of 12 computer chips is taken. What is the probability that the sample mean will be below 0.95 centimeters?

If the population distribution is unknown, in most cases the sampling distribution of the mean can be approximated by the normal distribution if the samples contain at least 30 observations.

Systematic samples are less efficient than a stratified sample.

To estimate the mean number of hours a student at a major university spent in the library, a researcher obtained the list of students from the registrar's office, from which she can select a random sample 200 students. This list is a ________.

The standard error of the population proportion will become larger

Which of the following is true about the sampling distribution of the sample mean?

Introduction

Organizing and Visualizing Data

Numerical Descriptive Measures

Basic Probability

Discrete Probability Distributions

The Normal Distribution and Other Continuous Distributions

Confidence Interval Estimation

Fundamentals of Hypothesis Testing: One-Sample Tests

Two-Sample Tests

Analysis of Variance

Chi-Square Tests and Nonparametric Tests

Simple Linear Regression

Introduction to Multiple Regression

Multiple Regression Model Building

Time-Series Forecasting

Statistical Applications in Quality Management

A Roadmap for Analyzing Data

Filters

The amount of bleach a machine pours into bottles has a mean of 36 oz. with a standard deviation of 0.15 oz. Suppose we take a random sample of 36 bottles filled by this machine. So, the middle 95% of the sample means based on samples of size 36 will be between and .

The standard error of the sampling distribution of a sample proportion is where $\sqrt{\frac{\rho(1-\rho)}{n}}$ ρ is the sample proportion.