Exam 9: The T Test for Independent Groups Samples

If the null hypothesis is true, then the t test should be close to:

A college student is interested in whether there is a difference between male and female students in the amount of time spent working out each week. The student gathers information from a random sample of male and female students on campus. The amount of time spent working out is normally distributed. The data are given below. -Conduct the appropriate analysis.

If an independent-groups t test is equal to zero, then:

A college student is interested in whether there is a difference between male and female students in the amount of time spent working out each week. The student gathers information from a random sample of male and female students on campus. The amount of time spent working out is normally distributed. The data are given below. -Calculate the 95% CI.

If an independent-groups t test has 10 subjects in each group, then the degrees of freedom are:

Imagine that you conducted an independent-groups t test with 15 subjects in each group. For a one-tailed test, the t_cv at $\alpha$ = .05 would be:

A student is interested in whether students who study with others devote as much attention to their studies as do students who study alone. He believes those who study alone devote more attention to their studies. He randomly assigns subjects to either group or individual study conditions and has them read and study the same passage of information for the same amount of time. Subjects are then all given the same 10-item test on the material. Their scores appear below. Scores on the test represent interval/ratio data and are normally distributed. -Should H₀ be rejected? What should the researcher conclude?

Which of the following is an assumption of the t test for independent groups?

A college student is interested in whether there is a difference between male and female students in the amount of time spent working out each week. The student gathers information from a random sample of male and female students on campus. The amount of time spent working out is normally distributed. The data are given below. -Identify H₀ and Ha for this study.

A researcher believes exercise reduces anxiety in women. She identifies a group of women who had not exercised before but are now planning to begin exercising. She gives them a 50-item anxiety inventory before they begin exercising and administers it again after six months of exercising. The anxiety inventory is measured on an interval scale and higher numbers indicate higher anxiety. In addition, scores on the inventory are normally distributed. The scores are given below. -The alternative hypothesis for a two-tailed independent-groups t test states that:

A college student is interested in whether there is a difference between male and female students in the amount of time spent working out each week. The student gathers information from a random sample of male and female students on campus. The amount of time spent working out is normally distributed. The data are given below. -What statistical test should be used to analyze these data?

A student is interested in whether students who study with others devote as much attention to their studies as do students who study alone. He believes those who study alone devote more attention to their studies. He randomly assigns subjects to either group or individual study conditions and has them read and study the same passage of information for the same amount of time. Subjects are then all given the same 10-item test on the material. Their scores appear below. Scores on the test represent interval/ratio data and are normally distributed. -Calculate the 95% CI.