Question 1

In the formula for finding a confidence interval when the value of the population standard deviation is unknown,we change N to N - 1.The reason for this change is

Accepted Answer

A) to correct for the fact that s is biased. 
B) the standard deviation of a sample is always greater than the standard deviation of the population. 
C) the standard deviation of a sample is unbiased. 
D) sample size is much too large. 
A) to correct for the fact that s is biased. 
B) the standard deviation of a sample is always greater than the standard deviation of the population. 
C) the standard deviation of a sample is unbiased. 
D) sample size is much too large.

Question 2

Sample size and the width of confidence intervals

Accepted Answer

A) increase at the same rate. 
B) increase at different rates: sample size increases faster than interval width. 
C) increase at different rates: sample size increases more slowly than interval width. 
D) have no relationship to each other. 
A) increase at the same rate. 
B) increase at different rates: sample size increases faster than interval width. 
C) increase at different rates: sample size increases more slowly than interval width. 
D) have no relationship to each other.

Question 3

To increase the probability that a confidence interval will include the population parameter,

Accepted Answer

A) lower the alpha level. 
B) raise the alpha level. 
C) increase the bias of the sample statistiC. 
D) set efficiency to zero. 
A) lower the alpha level. 
B) raise the alpha level. 
C) increase the bias of the sample statistiC. 
D) set efficiency to zero.

Question 4

The efficiency of a sample estimator is essentially a matter of

Accepted Answer

A) accuracy. 
B) validity. 
C) centrality. 
D) dispersion. 
A) accuracy. 
B) validity. 
C) centrality. 
D) dispersion.

Question 5

Instruction: For each situation below,construct the 95% confidence interval estimate to the population.Assume that the results are based on a nationally representative sample.Express the estimate in a sentence.
Refer to the instruction.The average years of school completed for 734 respondents was 11.9 with a standard deviation of 0.5.

Accepted Answer

11.9@#LAT-DLM& .04 or:The aver

Question 6

The greater the confidence level,the ____ width of the confidence interval

Accepted Answer

A) narrower 
B) more representative 
C) more efficient 
D) wider 
A) narrower 
B) more representative 
C) more efficient 
D) wider

Question 7

Polls tracking the presidential election of 2004 showed that

Accepted Answer

A) Bush lead by a clear margin from start to finish. 
B) Kerry lead by a clear margin until just a week before election day. 
C) the race was "too close to call" during much of the campaign. 
D) voter turnout would be extraordinarily high. 
A) Bush lead by a clear margin from start to finish. 
B) Kerry lead by a clear margin until just a week before election day. 
C) the race was "too close to call" during much of the campaign. 
D) voter turnout would be extraordinarily high.

Question 8

As sample size increases,confidence interval width

Accepted Answer

A) increases. 
B) decreases. 
C) remains the same. 
D) changes proportionally. 
A) increases. 
B) decreases. 
C) remains the same. 
D) changes proportionally.

Question 9

A random sample of 500 reports an average yearly income of $42,000 with a standard deviation of $1000.An estimate of the parameter at the 95% level is about $175 wide.In this research situation,

Accepted Answer

A) we can be 95% confident that the population mean is 42,000$\pm$ 175. 
B) the sample size is much too small to justify the use of estimation procedures. 
C) the alpha level is 1000. 
D) the sample mean is $175. 
A) we can be 95% confident that the population mean is 42,000$\pm$ 175. 
B) the sample size is much too small to justify the use of estimation procedures. 
C) the alpha level is 1000. 
D) the sample mean is $175.

Question 10

Instruction: For each situation below,construct the 95% confidence interval estimate to the population.Assume that the results are based on a nationally representative sample.Express the estimate in a sentence.
Refer to the instruction.Of the 998 respondents questioned,246 identified themselves as Catholic.

Accepted Answer

0.25@#LAT-DLM& 0.03 or:The per

Question 11

From a random sample of 300 state university students,you found that the average number of hours of study time each week is 30 with a standard deviation of 5.A point estimate of the average study time for all state university students would be

Accepted Answer

A) 5. 
B) 30. 
C) 300. 
D) 15$\pm$ 1 standard deviation. 
A) 5. 
B) 30. 
C) 300. 
D) 15$\pm$ 1 standard deviation.

Question 12

When using sample means as estimators,we usually estimate the population standard deviation with

Accepted Answer

A) the sample standard deviation. 
B) the sampling distribution standard deviation. 
C) the population parameter. 
D) the Z score. 
A) the sample standard deviation. 
B) the sampling distribution standard deviation. 
C) the population parameter. 
D) the Z score.

Question 13

To decrease the probability that a confidence interval will NOT include the population parameter,

Accepted Answer

A) lower the alpha level. 
B) raise the alpha level. 
C) increase the bias of the sample statistiC. 
D) set efficiency to zero. 
A) lower the alpha level. 
B) raise the alpha level. 
C) increase the bias of the sample statistiC. 
D) set efficiency to zero.

Question 14

Instruction: For each situation below,construct the 95% confidence interval estimate to the population.Assume that the results are based on a nationally representative sample.Express the estimate in a sentence.
Refer to the instruction.The average number of children for the 945 respondents for which we have information was 1.98 with a standard deviation of 1.04.

Accepted Answer

1.98@#LAT-DLM& .07 or:The aver

Question 15

In ____ of the cases,the mean of a sample selected by EPSEM will be more than$\pm$ 3 Z's from the population mean.

Accepted Answer

A) less than 1% 
B) more than 5% 
C) more than 90% 
D) more than 99% 
A) less than 1% 
B) more than 5% 
C) more than 90% 
D) more than 99%

Question 16

An estimator is unbiased if the mean of its sampling distribution is equal to

Accepted Answer

A) the midpoint of the distribution. 
B) the sample mean. 
C) the population value. 
D) the population median. 
A) the midpoint of the distribution. 
B) the sample mean. 
C) the population value. 
D) the population median.

Question 17

Instruction: For each situation below,construct the 95% confidence interval estimate to the population.Assume that the results are based on a nationally representative sample.Express the estimate in a sentence.
Refer to the instruction.Four hundred and thirty two of the 668 respondents questioned said that they favored capital punishment for people convicted of murder.Ten years ago,in response to the same question,378 out of 703 people were in favor of capital punishment.Has support for capital punishment risen over the ten year period?

Accepted Answer

Now:0.65@#LAT-DLM& .04 or:The percentage of the po

In the formula for finding a confidence interval when the value of the population standard deviation is unknown,we change N to N - 1.The reason for this change is

Sample size and the width of confidence intervals

To increase the probability that a confidence interval will include the population parameter,

The efficiency of a sample estimator is essentially a matter of

The greater the confidence level,the ____ width of the confidence interval

Polls tracking the presidential election of 2004 showed that

As sample size increases,confidence interval width

A random sample of 500 reports an average yearly income of $42,000 with a standard deviation of $1000.An estimate of the parameter at the 95% level is about $175 wide.In this research situation,

From a random sample of 300 state university students,you found that the average number of hours of study time each week is 30 with a standard deviation of 5.A point estimate of the average study time for all state university students would be

When using sample means as estimators,we usually estimate the population standard deviation with

To decrease the probability that a confidence interval will NOT include the population parameter,

In ____ of the cases,the mean of a sample selected by EPSEM will be more than $\pm$ 3 Z's from the population mean.

An estimator is unbiased if the mean of its sampling distribution is equal to

Introduction

Basic Descriptive Statistics: Percentages, Ratios and Rates, Tables, Charts and Graphs

Measures of Central Tendency

Measures of Dispersion

The Normal Curve

Introduction to Inferential Statistics: Sampling and the Sampling Distribution

Hypothesis Testing I: the One-Sample Case

Hypothesis Testing II: the Two-Sample Case

Hypothesis Testing III: the Analysis of Variance

Hypothesis Testing Iv: Chi Square

Bivariate Association: Introduction and Basic Concepts

Association Between Variables Measured at the Nominal Level

Association Between Variables Measured at the Ordinal Level

Association Between Variables Measured at the Interval-Ratio Level

Elaborating Bivariate Tables

Partial Correlation and Multiple Regression and Correlation

Filters

Exam 7: Estimation Procedures

In the formula for finding a confidence interval when the value of the population standard deviation is unknown,we change N to N - 1.The reason for this change is

Sample size and the width of confidence intervals

To increase the probability that a confidence interval will include the population parameter,

The efficiency of a sample estimator is essentially a matter of

The greater the confidence level,the ____ width of the confidence interval

Polls tracking the presidential election of 2004 showed that

As sample size increases,confidence interval width

A random sample of 500 reports an average yearly income of $42,000 with a standard deviation of $1000.An estimate of the parameter at the 95% level is about $175 wide.In this research situation,

From a random sample of 300 state university students,you found that the average number of hours of study time each week is 30 with a standard deviation of 5.A point estimate of the average study time for all state university students would be

When using sample means as estimators,we usually estimate the population standard deviation with

To decrease the probability that a confidence interval will NOT include the population parameter,

In ____ of the cases,the mean of a sample selected by EPSEM will be more than ±\pm± 3 Z's from the population mean.

An estimator is unbiased if the mean of its sampling distribution is equal to

Introduction

Basic Descriptive Statistics: Percentages, Ratios and Rates, Tables, Charts and Graphs

Measures of Central Tendency

Measures of Dispersion

The Normal Curve

Introduction to Inferential Statistics: Sampling and the Sampling Distribution

Hypothesis Testing I: the One-Sample Case

Hypothesis Testing II: the Two-Sample Case

Hypothesis Testing III: the Analysis of Variance

Hypothesis Testing Iv: Chi Square

Bivariate Association: Introduction and Basic Concepts

Association Between Variables Measured at the Nominal Level

Association Between Variables Measured at the Ordinal Level

Association Between Variables Measured at the Interval-Ratio Level

Elaborating Bivariate Tables

Partial Correlation and Multiple Regression and Correlation

Filters

In ____ of the cases,the mean of a sample selected by EPSEM will be more than $\pm$ 3 Z's from the population mean.