Problem Decide whether the sampling method is independent or dependent. Then determine whether the response variable is qualitative or quantitative.

(a) Joliet Junior College decided to implement a course redesign of its developmental mathematics program. Students either enrolled in a traditional lecture format course or a lab-based format in which lectures and homework are done using video and the course management system MyMathLab. There were 1200 students enrolled in the traditional lecture format and 300 enrolled in the lab-based format. Once the course ended, the researchers determined whether the student passed the course with an A, B, or C, or not. The goal of the study was to determine whether the proportion of students who passed the lab-based format exceeded that of the lecture format.

(b) Do women tend to select a spouse who has an IQ higher than their own? To answer this question, researchers randomly selected 20 women and their husbands. They measured the IQ of each husband-wife team to determine if there is a significant difference in IQ.

Approach Determine whether the individuals in one group were used to determine the individuals in the other group. If so, the sampling method is dependent. If not, the sampling method is independent. Finally, consider the response variable in the study. Is it qualitative with two outcomes? If so, inferential methods based on proportions are appropriate. Is it quantitative? If so, inferential methods based on means may be appropriate.