Question 1

When testing for the significance of the difference between two sample means, the null hypothesis is that

Accepted Answer

A)  the sample standard deviations are different 
B)  the sample means are different 
C)  the populations from which the sample were drawn are different 
D)  the populations from which the sample were drawn are the same 
A)  the sample standard deviations are different 
B)  the sample means are different 
C)  the populations from which the sample were drawn are different 
D)  the populations from which the sample were drawn are the same

Question 2

From a university population, random samples of 45 seniors and 37 freshmen have been given a scale that measures sexual experiences. The freshmen report an average of 1.6 sexual partners over their lifetimes while seniors report an average of 2.5 partners. The t (obtained) for this difference was -3.56 while the t (critical) was $\pm$2.34. What can be concluded?

Accepted Answer

A)  there is no significant difference between the classes 
B)  seniors and freshman are significantly different in their sexual experiences 
C)  freshman are more sexually active 
D)  sexual mores are deteriorating 
A)  there is no significant difference between the classes 
B)  seniors and freshman are significantly different in their sexual experiences 
C)  freshman are more sexually active 
D)  sexual mores are deteriorating

Question 3

Samples of Republicans and Democrats have been tested for their level of support for welfare reform and the null hypothesis has been rejected. What may we conclude?

Accepted Answer

A)  the difference is significant, there are differences between the parties on this issue 
B)  the difference is significant, the parties are the same on this issue 
C)  the difference is not significant 
D)  a Type I error has occurred 
A)  the difference is significant, there are differences between the parties on this issue 
B)  the difference is significant, the parties are the same on this issue 
C)  the difference is not significant 
D)  a Type I error has occurred

Question 4

Since critical values of t vary by sample size, before using the t table we must first calculate

Accepted Answer

A)  the Z score 
B)  degrees of freedom 
C)  the population standard deviation 
D)  the alpha level 
A)  the Z score 
B)  degrees of freedom 
C)  the population standard deviation 
D)  the alpha level

Question 5

When testing for the significance of the difference between two sample means, the standard deviation of the sampling distribution is estimated using

Accepted Answer

A)  population standard deviations 
B)  the standard error of the means 
C)  degrees of freedom 
D)  sample standard deviations corrected for bias 
A)  population standard deviations 
B)  the standard error of the means 
C)  degrees of freedom 
D)  sample standard deviations corrected for bias

Question 6

When conducting hypothesis tests for two sample means, the term $\mu$1 - $\mu$2 in the numerator of the formula reduces to zero because

Accepted Answer

A)  the standard deviations are calculated first 
B)  the tests are conducted at very low alpha levels 
C)  the samples are independent as well as random 
D)  the null hypothesis is assumed to be true 
A)  the standard deviations are calculated first 
B)  the tests are conducted at very low alpha levels 
C)  the samples are independent as well as random 
D)  the null hypothesis is assumed to be true

Question 7

When testing for the significance of the difference between two samples, the null hypothesis states that the ____________ are the same

Accepted Answer

A)  sample means 
B)  population means 
C)  sampling distributions 
D)  population standard deviations 
A)  sample means 
B)  population means 
C)  sampling distributions 
D)  population standard deviations

Question 8

According to the text, on the issue of abortion,

Accepted Answer

A)  Democratic and Republican opinion has grown increasingly alike over the years 
B)  Democratic and Republican opinion has grown increasingly apart over the years 
C)  Democratic women have become increasingly like Republican women 
D)  Young Democrats and young Republicans have become increasingly alike 
A)  Democratic and Republican opinion has grown increasingly alike over the years 
B)  Democratic and Republican opinion has grown increasingly apart over the years 
C)  Democratic women have become increasingly like Republican women 
D)  Young Democrats and young Republicans have become increasingly alike

Question 9

Random samples of men and women have been given a scale that measures their support for gun control. Men average 10.2 with standard deviation of 5.3. Women also average 10.2 but their standard deviation is 1.8. How could these results be dealt with appropriately?

Accepted Answer

A)  test the difference in the sample means for statistical significance 
B)  since the sample means are the same value, there is no need to conduct any tests; these results cannot be significant 
C)  a one-tailed test of significance is called for 
D)  a test of significance with a very high alpha level ($\alpha$ > 0.10) is called for 
A)  test the difference in the sample means for statistical significance 
B)  since the sample means are the same value, there is no need to conduct any tests; these results cannot be significant 
C)  a one-tailed test of significance is called for 
D)  a test of significance with a very high alpha level ($\alpha$ > 0.10) is called for

When testing for the significance of the difference between two sample means, the null hypothesis is that

Samples of Republicans and Democrats have been tested for their level of support for welfare reform and the null hypothesis has been rejected. What may we conclude?

Since critical values of t vary by sample size, before using the t table we must first calculate

When testing for the significance of the difference between two sample means, the standard deviation of the sampling distribution is estimated using

When conducting hypothesis tests for two sample means, the term $\mu$ 1 - $\mu$ 2 in the numerator of the formula reduces to zero because

When testing for the significance of the difference between two samples, the null hypothesis states that the ____________ are the same

According to the text, on the issue of abortion,

Random samples of men and women have been given a scale that measures their support for gun control. Men average 10.2 with standard deviation of 5.3. Women also average 10.2 but their standard deviation is 1.8. How could these results be dealt with appropriately?

Introduction

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

Measures of Central Tendency

Measures of Dispersion

The Normal Curve

Introduction to Inferential Statistics Sampling the Sampling Distribution

Hypothesis Testing I the One-Sample Case

Hypothesis Testing III: the Analysis of Variance

Hypothesis Testing Iv Chi Square

Bivariate Association for Nominal- and Ordinal-Level Variables

Association Between Variables Measured at the Interval-Ratio Level

Partial Correlation and

Filters

Exam 8: Hypothesis Testing II the Two-Sample Case

When testing for the significance of the difference between two sample means, the null hypothesis is that

Samples of Republicans and Democrats have been tested for their level of support for welfare reform and the null hypothesis has been rejected. What may we conclude?

Since critical values of t vary by sample size, before using the t table we must first calculate

When testing for the significance of the difference between two sample means, the standard deviation of the sampling distribution is estimated using

When conducting hypothesis tests for two sample means, the term μ\muμ 1 - μ\muμ 2 in the numerator of the formula reduces to zero because

When testing for the significance of the difference between two samples, the null hypothesis states that the ____________ are the same

According to the text, on the issue of abortion,

Random samples of men and women have been given a scale that measures their support for gun control. Men average 10.2 with standard deviation of 5.3. Women also average 10.2 but their standard deviation is 1.8. How could these results be dealt with appropriately?

Introduction

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

Measures of Central Tendency

Measures of Dispersion

The Normal Curve

Introduction to Inferential Statistics Sampling the Sampling Distribution

Hypothesis Testing I the One-Sample Case

Hypothesis Testing III: the Analysis of Variance

Hypothesis Testing Iv Chi Square

Bivariate Association for Nominal- and Ordinal-Level Variables

Association Between Variables Measured at the Interval-Ratio Level

Partial Correlation and

Filters

When conducting hypothesis tests for two sample means, the term $\mu$ 1 - $\mu$ 2 in the numerator of the formula reduces to zero because