A Sociologist Has Been Studying College Instructors and Is Especially

Multiple Choice

A sociologist has been studying college instructors and is especially interested in those instructors who teach night classes. Amongst others, he collected data on the course grade from the student evaluations and the highest level of education the instructor has completed (Master or Ph.D.) . If the sociologist wishes to determine how much higher the course grades are for courses taught by an instructor with a Ph.D. than those taught by an instructor with a master's degree, which inference procedure should he use?

A) A t-test about the difference between two means for independent samples.
B) A t-test about the mean difference for paired data.
C) A confidence interval for the difference between two means for independent samples.
D) A confidence interval for the mean difference for paired data.