Question 1

What are the two population parameters that specify the location and dispersion for a normal distribution?

Accepted Answer

µ, the population me

Question 2

All possible samples of size n are selected from a population and the mean of each sample is determined. What is the mean of the sample means?

Accepted Answer

A) The population mean. 
B) It is larger than the population mean. 
C) It is smaller than the population mean. 
D) It cannot be estimated in advance. 
A) The population mean. 
B) It is larger than the population mean. 
C) It is smaller than the population mean. 
D) It cannot be estimated in advance.

Question 3

Bones Brothers & Associates prepare individual tax returns. Over prior years, Bones Brothers has maintained careful records regarding the time to prepare a return. The mean time to prepare a return is 90 minutes and the standard deviation of this distribution is 14 minutes. Suppose 100 returns from this year are selected and analyzed regarding the preparation time. What is the probability that the mean time for the sample of 100 returns is between 88 minutes and 92 minutes?

Accepted Answer

A) Approximately 1 
B) 0.1664 
C) 0.8336 
D) 0.8472 
A) Approximately 1 
B) 0.1664 
C) 0.8336 
D) 0.8472

Question 4

As the size of the sample increases, what happens to the shape of the distribution of sample means?

Accepted Answer

A) It cannot be predicted in advance. 
B) It approaches a normal distribution. 
C) It is positively skewed. 
D) It is negatively skewed. 
A) It cannot be predicted in advance. 
B) It approaches a normal distribution. 
C) It is positively skewed. 
D) It is negatively skewed.

Question 5

When doing research, knowing the population mean and other population parameters is essential.

Accepted Answer

A) True 
 B)False

Question 6

The tread life of tires mounted on light-duty trucks follows the normal probability distribution with a mean of 60,000 miles and a standard deviation of 4,000 miles. Suppose we select a sample of 40 tires and use a simulator to determine the tread life. What is the likelihood of finding that the sample mean is between 59,050 and 60,950?

Accepted Answer

A) 0.4332 
B) 0.8664 
C) 1.00 
D) Very likely 
A) 0.4332 
B) 0.8664 
C) 1.00 
D) Very likely

Question 7

In the sampling distribution of the sample means, the standard error of the mean will vary according to the size of the sample. As the sample size, n, gets larger, the variability of the sampling distribution of the means gets larger.

Accepted Answer

A) True 
 B)False

Question 8

A sampling distribution of the means is a probability distribution consisting of all possible sample means of a given sample size selected from a population.

Accepted Answer

A) True 
 B)False

Question 9

A population consists of 15 values. How many samples of size 10 are possible?

Accepted Answer

The answer of A population consists of 15 values. How...

Question 10

Mileage tests were conducted on a randomly selected sample of 100 newly developed automobile tires. The mean tread wear was 50,000 miles, with a standard deviation of 3,500 miles. What is the best estimate of the average tread life in miles for the entire population of these tires?

Accepted Answer

A) 50,000 
B) 3,500 
C) 500 
D) 35 
A) 50,000 
B) 3,500 
C) 500 
D) 35

Question 11

The wildlife department has been feeding a special food to rainbow trout fingerlings in a pond. Based on a large number of observations, the distribution of trout weights is normally distributed with a mean of 402.7 grams and a standard deviation 8.8 grams. What is the probability that the mean weight for a sample of 40 trout exceeds 405.5 grams?

Accepted Answer

A) 0.3782 
B) 0.0222 
C) 1.0 
D) 0.5 
A) 0.3782 
B) 0.0222 
C) 1.0 
D) 0.5

Question 12

The standard deviation of the sampling distribution of the sample means is called the ______________.

Accepted Answer

Standard e

Question 13

For a given population, the mean of all the sample means   of sample size n, and the mean of all (N) population observations (X) are _______.

Accepted Answer

A) Equal to   
B) Not equal 
C) Equal to   
D) Equal to the population mean µ 
A) Equal to   
B) Not equal 
C) Equal to   
D) Equal to the population mean µ

Question 14

A population consists of the following five values: 3, 8, 11, 13, and 16. From this population, there are 10 different samples of size 3. The means of the 10 samples of size 3 are 7.33, 8, 9, 9, 10, 10.67, 10.67, 11.67, 12.33, and 13.33. Compare the dispersion in the population with that of the sample means.

Accepted Answer

The range of the population is

Question 15

The size of the sampling error is ________.

Accepted Answer

A) Directly related to the sample size-in other words, the larger the sample size, the larger the sampling error 
B) Directly related to the population mean-in other words, the larger the mean, the larger the sampling error 
C) Inversely related to the sample size-in other words, the larger the sample size, the smaller the sampling error 
D) Inversely related to the population standard deviation-in other words, the smaller the standard deviation, the larger the sampling error 
A) Directly related to the sample size-in other words, the larger the sample size, the larger the sampling error 
B) Directly related to the population mean-in other words, the larger the mean, the larger the sampling error 
C) Inversely related to the sample size-in other words, the larger the sample size, the smaller the sampling error 
D) Inversely related to the population standard deviation-in other words, the smaller the standard deviation, the larger the sampling error

Question 16

When dividing a population into subgroups so that a random sample from each subgroup can be collected, what type of sampling is used?

Accepted Answer

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

Question 17

If a population is normally distributed, then the sampling distribution of the sample means will be __________________________.

Accepted Answer

Normally d

Question 18

The Office of Student Services at a large western state university maintains information on the study habits of its full-time students. Their studies indicate that the mean amount of time undergraduate students study per week is 20 hours. The hours studied follows the normal distribution with a standard deviation of six hours. Suppose we select a random sample of 144 current students. What is the standard error of the mean?

Accepted Answer

A) 0.50 
B) 6.00 
C) 0.25 
D) 2.00 
A) 0.50 
B) 6.00 
C) 0.25 
D) 2.00

Question 19

LongLast Inc. produces car batteries. The mean life of these batteries is 60 months. The distribution of the battery life closely follows the normal probability distribution with a standard deviation of eight months. As a part of its testing program, LongLast tests a sample of 25 batteries. What proportion of the samples will have a mean useful life between 58 and 62 months?

Accepted Answer

The answer of LongLast Inc. produces car batteries. The mean...

Question 20

For a sampling distribution of the means, about ________% of the means would be between ±1.96 standard deviations.

Accepted Answer

The answer of For a sampling distribution of the means,...

What are the two population parameters that specify the location and dispersion for a normal distribution?

All possible samples of size n are selected from a population and the mean of each sample is determined. What is the mean of the sample means?

As the size of the sample increases, what happens to the shape of the distribution of sample means?

When doing research, knowing the population mean and other population parameters is essential.

In the sampling distribution of the sample means, the standard error of the mean will vary according to the size of the sample. As the sample size, n, gets larger, the variability of the sampling distribution of the means gets larger.

A sampling distribution of the means is a probability distribution consisting of all possible sample means of a given sample size selected from a population.

A population consists of 15 values. How many samples of size 10 are possible?

Mileage tests were conducted on a randomly selected sample of 100 newly developed automobile tires. The mean tread wear was 50,000 miles, with a standard deviation of 3,500 miles. What is the best estimate of the average tread life in miles for the entire population of these tires?

The standard deviation of the sampling distribution of the sample means is called the ______________.

For a given population, the mean of all the sample means of sample size n, and the mean of all (N) population observations (X) are _______.

The size of the sampling error is ________.

When dividing a population into subgroups so that a random sample from each subgroup can be collected, what type of sampling is used?

If a population is normally distributed, then the sampling distribution of the sample means will be __________________________.

For a sampling distribution of the means, about ________% of the means would be between ±1.96 standard deviations.

What Is Statistics

Describing Data: Frequency Tables, Frequency Distributions, and Graphic Presentation

Describing Data: Numerical Measures

Describing Data: Displaying and Exploring Data

A Survey of Probability Concepts

Discrete Probability Distributions

Continuous Probability Distributions

Estimation and Confidence Intervals

One-Sample Tests of Hypothesis

Two-Sample Tests of Hypothesis

Analysis of Variance

Correlation and Linear Regression

Multiple Regression Analysis

Nonparametric Methods: Goodness-Of-Fit Tests

Filters

Exam 8: Sampling Methods and the Central Limit Theorem

What are the two population parameters that specify the location and dispersion for a normal distribution?

All possible samples of size n are selected from a population and the mean of each sample is determined. What is the mean of the sample means?

As the size of the sample increases, what happens to the shape of the distribution of sample means?

When doing research, knowing the population mean and other population parameters is essential.

In the sampling distribution of the sample means, the standard error of the mean will vary according to the size of the sample. As the sample size, n, gets larger, the variability of the sampling distribution of the means gets larger.

A sampling distribution of the means is a probability distribution consisting of all possible sample means of a given sample size selected from a population.

A population consists of 15 values. How many samples of size 10 are possible?

Mileage tests were conducted on a randomly selected sample of 100 newly developed automobile tires. The mean tread wear was 50,000 miles, with a standard deviation of 3,500 miles. What is the best estimate of the average tread life in miles for the entire population of these tires?

The standard deviation of the sampling distribution of the sample means is called the ______________.

For a given population, the mean of all the sample means of sample size n, and the mean of all (N) population observations (X) are _______.

The size of the sampling error is ________.

When dividing a population into subgroups so that a random sample from each subgroup can be collected, what type of sampling is used?

If a population is normally distributed, then the sampling distribution of the sample means will be __________________________.

For a sampling distribution of the means, about ________% of the means would be between ±1.96 standard deviations.

What Is Statistics

Describing Data: Frequency Tables, Frequency Distributions, and Graphic Presentation

Describing Data: Numerical Measures

Describing Data: Displaying and Exploring Data

A Survey of Probability Concepts

Discrete Probability Distributions

Continuous Probability Distributions

Estimation and Confidence Intervals

One-Sample Tests of Hypothesis

Two-Sample Tests of Hypothesis

Analysis of Variance

Correlation and Linear Regression

Multiple Regression Analysis

Nonparametric Methods: Goodness-Of-Fit Tests

Filters