Question 1

Confidence intervals are a function of the

Accepted Answer

A) population,the sample,and the standard deviation. 
B) sample,the variable of interest,and the degrees of freedom. 
C) data in the sample,the confidence level,and the sample size. 
D) sampling distribution,the confidence level,and the degrees of freedom. 
A) population,the sample,and the standard deviation. 
B) sample,the variable of interest,and the degrees of freedom. 
C) data in the sample,the confidence level,and the sample size. 
D) sampling distribution,the confidence level,and the degrees of freedom.

Question 2

If the standard error of the sampling distribution of the sample proportion   is 0.0324 for samples of size 200,then the population proportion must be 0.30.

Accepted Answer

A) True 
 B)False

Question 3

A confidence interval is an interval that,with a stated level of confidence,captures a population parameter.

Accepted Answer

A) True 
 B)False

Question 4

Two independent samples of sizes 20 and 25 are randomly selected from two normal populations with equal variances.In order to test the difference between the population means,the test statistic is

Accepted Answer

A) a standard normal random variable. 
B) an approximately standard normal random variable. 
C) t-distributed with 45 degrees of freedom. 
D) t-distributed with 43 degrees of freedom. 
A) a standard normal random variable. 
B) an approximately standard normal random variable. 
C) t-distributed with 45 degrees of freedom. 
D) t-distributed with 43 degrees of freedom.

Question 5

The chi-square distribution for developing a confidence interval for a standard deviation has degrees of freedom equal to

Accepted Answer

A) n + 2. 
B) n +1. 
C) n. 
D) n - 1. 
A) n + 2. 
B) n +1. 
C) n. 
D) n - 1.

Question 6

You would like to estimate the average amount a family spends on food during a year.In the past,the standard deviation of the amount a family has spent on food during a year has been approximately $800.If you want to be 95% sure that you estimated average family food expenditures within $50,how many families do you need to survey?

Accepted Answer

@#IMG-DLM& = 800,B = 50,z - multiple = 1

Question 7

Generally speaking,the two types of statistical inference are

Accepted Answer

A) sample estimation and population estimation. 
B) confidence interval estimation and hypothesis testing. 
C) the interval estimation for a mean and the point estimation for a proportion. 
D) independent sample estimation and dependent sample estimation. 
A) sample estimation and population estimation. 
B) confidence interval estimation and hypothesis testing. 
C) the interval estimation for a mean and the point estimation for a proportion. 
D) independent sample estimation and dependent sample estimation.

Question 8

In general,increasing the confidence level will narrow the confidence interval,and decreasing the confidence level widens the interval.

Accepted Answer

A) True 
 B)False

Question 9

In developing a confidence interval for the population standard deviation   ,we make use of the fact that the sampling distribution of the sample standard deviation s is not the normal distribution or the t-distribution,but rather a right-skewed distribution called the chi-square distribution,which (for this procedure)has n - 1 degrees of freedom.

Accepted Answer

A) True 
 B)False

Question 10

If two random samples of size 40 each are selected independently from two populations whose variances are 35 and 45,then the standard error of the sampling distribution of the sample mean difference,   ,equals 1.4142.

Accepted Answer

A) True 
 B)False

Question 11

When you calculate the sample size for a proportion,you use an estimate for the population proportion; namely   .A conservative value for n can be obtained by using

Accepted Answer

A) 0.01. 
B) 0.05. 
C) 0.10. 
D) 0.50. 
A) 0.01. 
B) 0.05. 
C) 0.10. 
D) 0.50.

Question 12

Suppose there are 500 accounts in a population.You sample 50 of them and find a sample mean of $500.What would be your estimate for the population total?

Accepted Answer

A) $5,000 
B) $50,000 
C) $250,000 
D) $500,000 
A) $5,000 
B) $50,000 
C) $250,000 
D) $500,000

Question 13

The interval estimate 18.5   2.5 is developed for a population mean in which the sample standard deviation s is 7.5.Had s equaled 15 instead,the interval estimate would be 37   5.0.

Accepted Answer

A) True 
 B)False

Question 14

If two samples contain the same number of observations,then the data must be paired.

Accepted Answer

A) True 
 B)False

Question 15

You are attempting to estimate the average amount a family spends on food during a year.In the past,the standard deviation of the amount a family has spent on food during a year has been approximately $1200.If you want to be 99% sure that you have estimated average family food expenditures within $60,how many families do you need to survey?

Accepted Answer

@#IMG-DLM& =1200,z - multiple

Question 16

If a random sample of size 250 is taken from a population,where it is known that the population proportion p = 0.4,then the mean of the sampling distribution of the sample proportion   is 0.60.

Accepted Answer

A) True 
 B)False

Question 17

If you are constructing a confidence interval for a single mean,the length of the confidence interval will _____ with an increase in the sample size.

Accepted Answer

A) decrease 
B) increase 
C) stay the same 
D) increase or decrease,depending on the sample data, 
A) decrease 
B) increase 
C) stay the same 
D) increase or decrease,depending on the sample data,

Question 18

As a general rule,the normal distribution is used to approximate the sampling distribution of the sample proportion   only if the sample size n is greater than 30.

Accepted Answer

A) True 
 B)False

Question 19

If two random samples of sizes 30 and 35 are selected independently from two populations whose means are 85 and 90,then the mean of the sampling distribution of the sample mean difference,   ,equals 5.

Accepted Answer

A) True 
 B)False

Question 20

If we cannot make the strong assumption that the variances of two samples are equal,then we must use the pooled standard deviation in calculating the standard error of a difference between the means.

Accepted Answer

A) True 
 B)False

Confidence intervals are a function of the

If the standard error of the sampling distribution of the sample proportion is 0.0324 for samples of size 200,then the population proportion must be 0.30.

A confidence interval is an interval that,with a stated level of confidence,captures a population parameter.

Two independent samples of sizes 20 and 25 are randomly selected from two normal populations with equal variances.In order to test the difference between the population means,the test statistic is

The chi-square distribution for developing a confidence interval for a standard deviation has degrees of freedom equal to

Generally speaking,the two types of statistical inference are

In general,increasing the confidence level will narrow the confidence interval,and decreasing the confidence level widens the interval.

If two random samples of size 40 each are selected independently from two populations whose variances are 35 and 45,then the standard error of the sampling distribution of the sample mean difference, ,equals 1.4142.

When you calculate the sample size for a proportion,you use an estimate for the population proportion; namely .A conservative value for n can be obtained by using

Suppose there are 500 accounts in a population.You sample 50 of them and find a sample mean of $500.What would be your estimate for the population total?

The interval estimate 18.5 2.5 is developed for a population mean in which the sample standard deviation s is 7.5.Had s equaled 15 instead,the interval estimate would be 37 5.0.

If two samples contain the same number of observations,then the data must be paired.

If a random sample of size 250 is taken from a population,where it is known that the population proportion p = 0.4,then the mean of the sampling distribution of the sample proportion is 0.60.

If you are constructing a confidence interval for a single mean,the length of the confidence interval will _____ with an increase in the sample size.

As a general rule,the normal distribution is used to approximate the sampling distribution of the sample proportion only if the sample size n is greater than 30.

If two random samples of sizes 30 and 35 are selected independently from two populations whose means are 85 and 90,then the mean of the sampling distribution of the sample mean difference, ,equals 5.

If we cannot make the strong assumption that the variances of two samples are equal,then we must use the pooled standard deviation in calculating the standard error of a difference between the means.

Introduction to Business Analytics

Describing the Distribution of a Variable

Finding Relationships Among Variables

Business Intelligence Bifor Data Analysis

Probability and Probability Distributions

Decision Making Under Uncertainty

Sampling and Sampling Distributions

Hypothesis Testing

Regression Analysis: Estimating Relationships

Regression Analysis: Statistical Inference

Time Series Analysis and Forecasting

Introduction to Optimization Modeling

Optimization Models

Introduction to Simulation Modeling

Simulation Models

Data Mining

Analysis of Variance and Experimental Design

Statistical Process Control

Filters

Exam 8: Confidence Interval Estimation

Confidence intervals are a function of the

If the standard error of the sampling distribution of the sample proportion is 0.0324 for samples of size 200,then the population proportion must be 0.30.

A confidence interval is an interval that,with a stated level of confidence,captures a population parameter.

Two independent samples of sizes 20 and 25 are randomly selected from two normal populations with equal variances.In order to test the difference between the population means,the test statistic is

The chi-square distribution for developing a confidence interval for a standard deviation has degrees of freedom equal to

Generally speaking,the two types of statistical inference are

In general,increasing the confidence level will narrow the confidence interval,and decreasing the confidence level widens the interval.

If two random samples of size 40 each are selected independently from two populations whose variances are 35 and 45,then the standard error of the sampling distribution of the sample mean difference, ,equals 1.4142.

When you calculate the sample size for a proportion,you use an estimate for the population proportion; namely .A conservative value for n can be obtained by using

Suppose there are 500 accounts in a population.You sample 50 of them and find a sample mean of $500.What would be your estimate for the population total?

The interval estimate 18.5 2.5 is developed for a population mean in which the sample standard deviation s is 7.5.Had s equaled 15 instead,the interval estimate would be 37 5.0.

If two samples contain the same number of observations,then the data must be paired.

If a random sample of size 250 is taken from a population,where it is known that the population proportion p = 0.4,then the mean of the sampling distribution of the sample proportion is 0.60.

If you are constructing a confidence interval for a single mean,the length of the confidence interval will _____ with an increase in the sample size.

As a general rule,the normal distribution is used to approximate the sampling distribution of the sample proportion only if the sample size n is greater than 30.

If two random samples of sizes 30 and 35 are selected independently from two populations whose means are 85 and 90,then the mean of the sampling distribution of the sample mean difference, ,equals 5.

If we cannot make the strong assumption that the variances of two samples are equal,then we must use the pooled standard deviation in calculating the standard error of a difference between the means.

Introduction to Business Analytics

Describing the Distribution of a Variable

Finding Relationships Among Variables

Business Intelligence Bifor Data Analysis

Probability and Probability Distributions

Decision Making Under Uncertainty

Sampling and Sampling Distributions

Hypothesis Testing

Regression Analysis: Estimating Relationships

Regression Analysis: Statistical Inference

Time Series Analysis and Forecasting

Introduction to Optimization Modeling

Optimization Models

Introduction to Simulation Modeling

Simulation Models

Data Mining

Analysis of Variance and Experimental Design

Statistical Process Control

Filters