Question 1

A parameter such as   is sometimes referred to as a(n)_____ parameter,because many times,we need its value even though it is not the parameter of primary interest.

Accepted Answer

A) dependent 
B) random 
C) nuisance 
D) independent 
A) dependent 
B) random 
C) nuisance 
D) independent C

Question 2

A 90% confidence interval estimate for a population mean   is determined to be 72.8 to 79.6.If the confidence level is reduced to 80%,the confidence interval for   becomes narrower.

Accepted Answer

A) True 
 B)False  True

Question 3

The t-distribution for developing a confidence interval for a mean 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. D

Question 4

The approximate standard error of the point estimate of the population total is

Accepted Answer

A)    . 
B)    . 
C)    . 
D)    . 
A)    . 
B)    . 
C)    . 
D)    .

Question 5

The confidence interval for the population standard deviation σ is centered at the point estimate,the sample standard deviation s.

Accepted Answer

A) True 
 B)False

Question 6

In determining the sample size n for estimating the population proportion p,a conservative value of n can be obtained by using 0.50 as an estimate of p.

Accepted Answer

A) True 
 B)False

Question 7

For a given confidence level,the procedure for controlling interval length usually begins with the specification of the

Accepted Answer

A) point estimate. 
B) population standard deviation,s. 
C) sample standard deviation,s. 
D) interval half-length,B. 
A) point estimate. 
B) population standard deviation,s. 
C) sample standard deviation,s. 
D) interval half-length,B.

Question 8

In general,the paired-sample procedure is appropriate when the samples are naturally paired in some way and there is a reasonably large positive correlation between the pairs.In this case,the paired-sample procedure makes more efficient use of the data and generally results in narrower confidence intervals.

Accepted Answer

A) True 
 B)False

Question 9

In past years,approximately 25% of all U.S.families purchased potato chips at least once a month.We are interested in determining the fraction of all U.S.families that currently purchase potato chips at least once a month.How many families must we survey if we want to be 99% sure that our estimate of the fraction of U.S.families currently purchasing potato chips at least once a month is accurate within 2%?

Accepted Answer

@#IMG-DLM& = 0.25,z - multiple = 2.575,B

Question 10

When calculating a confidence interval for the difference between two population proportions,we multiply the standard error of the difference between sample proportions by t-multiple.

Accepted Answer

A) True 
 B)False

Question 11

The degrees of freedom for the t and chi-square distributions is a numerical parameter of the distribution that defines the precise shape of the distribution.

Accepted Answer

A) True 
 B)False

Question 12

In order to construct a confidence interval estimate of the population mean   ,the value of   must be given.

Accepted Answer

A) True 
 B)False

Question 13

When we replace   with the sample standard deviation (s),we introduce a new source of variability and the sampling distribution becomes the

Accepted Answer

A) t -distribution. 
B) F- distribution. 
C) chi-square distribution. 
D) normal distribution. 
A) t -distribution. 
B) F- distribution. 
C) chi-square distribution. 
D) normal distribution.

Question 14

The standard error of the sampling distribution of the sample proportion   ,when the sample size n = 50 and the population proportion p = 0.25,is 0.00375.

Accepted Answer

A) True 
 B)False

Question 15

The shape of a chi-square distribution

Accepted Answer

A) is symmetric. 
B) is skewed to the left. 
C) is skewed to the right. 
D) depends on the sample data. 
A) is symmetric. 
B) is skewed to the left. 
C) is skewed to the right. 
D) depends on the sample data.

Question 16

In developing a confidence interval for the difference between two population means using two independent samples,we use the pooled estimate   in estimating the standard error of the sampling distribution of the sample mean difference   if the populations are normal with equal variances.

Accepted Answer

A) True 
 B)False

Question 17

If you increase the confidence level,the length of the confidence interval

Accepted Answer

A) decreases. 
B) increases. 
C) stays the same. 
D) may increase or decrease,depending on the sample data. 
A) decreases. 
B) increases. 
C) stays the same. 
D) may increase or decrease,depending on the sample data.

Question 18

Two independent samples of sizes 50 and 50 are randomly selected from two populations to test the difference between the population means,   .The sampling distribution of the sample mean difference   is

Accepted Answer

A) normally distributed. 
B) approximately normal. 
C) t - distributed with 98 degrees of freedom. 
D) chi-squared distributed with 99 degrees of freedom. 
A) normally distributed. 
B) approximately normal. 
C) t - distributed with 98 degrees of freedom. 
D) chi-squared distributed with 99 degrees of freedom.

Question 19

The approximate standard error of the point estimate of the population total is   .

Accepted Answer

A) True 
 B)False

Question 20

When the samples we want to compare pair in some natural way,such as a pretest/posttest for each person or husband/wife pairs,a more appropriate form of analysis is to not construct a confidence interval treating them as two separate variables,but instead to construct a confidence interval to estimate the mean

Accepted Answer

A) difference. 
B) sum. 
C) ratio. 
D) total. 
A) difference. 
B) sum. 
C) ratio. 
D) total.

A parameter such as is sometimes referred to as a(n)_____ parameter,because many times,we need its value even though it is not the parameter of primary interest.

A 90% confidence interval estimate for a population mean is determined to be 72.8 to 79.6.If the confidence level is reduced to 80%,the confidence interval for becomes narrower.

The t-distribution for developing a confidence interval for a mean has degrees of freedom equal to

The approximate standard error of the point estimate of the population total is

The confidence interval for the population standard deviation σ is centered at the point estimate,the sample standard deviation s.

In determining the sample size n for estimating the population proportion p,a conservative value of n can be obtained by using 0.50 as an estimate of p.

For a given confidence level,the procedure for controlling interval length usually begins with the specification of the

When calculating a confidence interval for the difference between two population proportions,we multiply the standard error of the difference between sample proportions by t-multiple.

The degrees of freedom for the t and chi-square distributions is a numerical parameter of the distribution that defines the precise shape of the distribution.

In order to construct a confidence interval estimate of the population mean ,the value of must be given.

When we replace with the sample standard deviation (s),we introduce a new source of variability and the sampling distribution becomes the

The standard error of the sampling distribution of the sample proportion ,when the sample size n = 50 and the population proportion p = 0.25,is 0.00375.

The shape of a chi-square distribution

In developing a confidence interval for the difference between two population means using two independent samples,we use the pooled estimate in estimating the standard error of the sampling distribution of the sample mean difference if the populations are normal with equal variances.

If you increase the confidence level,the length of the confidence interval

Two independent samples of sizes 50 and 50 are randomly selected from two populations to test the difference between the population means, .The sampling distribution of the sample mean difference is

The approximate standard error of the point estimate of the population total is .

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

A parameter such as is sometimes referred to as a(n)_____ parameter,because many times,we need its value even though it is not the parameter of primary interest.

A 90% confidence interval estimate for a population mean is determined to be 72.8 to 79.6.If the confidence level is reduced to 80%,the confidence interval for becomes narrower.

The t-distribution for developing a confidence interval for a mean has degrees of freedom equal to

The approximate standard error of the point estimate of the population total is

The confidence interval for the population standard deviation σ is centered at the point estimate,the sample standard deviation s.

In determining the sample size n for estimating the population proportion p,a conservative value of n can be obtained by using 0.50 as an estimate of p.

For a given confidence level,the procedure for controlling interval length usually begins with the specification of the

When calculating a confidence interval for the difference between two population proportions,we multiply the standard error of the difference between sample proportions by t-multiple.

The degrees of freedom for the t and chi-square distributions is a numerical parameter of the distribution that defines the precise shape of the distribution.

In order to construct a confidence interval estimate of the population mean ,the value of must be given.

When we replace with the sample standard deviation (s),we introduce a new source of variability and the sampling distribution becomes the

The standard error of the sampling distribution of the sample proportion ,when the sample size n = 50 and the population proportion p = 0.25,is 0.00375.

The shape of a chi-square distribution

In developing a confidence interval for the difference between two population means using two independent samples,we use the pooled estimate in estimating the standard error of the sampling distribution of the sample mean difference if the populations are normal with equal variances.

If you increase the confidence level,the length of the confidence interval

Two independent samples of sizes 50 and 50 are randomly selected from two populations to test the difference between the population means, .The sampling distribution of the sample mean difference is

The approximate standard error of the point estimate of the population total is .

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