Reconsider the previous exercises about the study of whether there is an association between number of Facebook friends and a person’s sex.

a. Use the 2SD method and the information available in the previous exercises to find a 95% confidence interval for the difference in average number of Facebook friends that men have and that women have.
b. Interpret the confidence interval reported in part (a) in the context of the study.

Data from previous exercise

The p-value for the randomization-based test of whether the average number of Facebook friends men have is different from that of women turns out to be 0.052.

In a survey of introductory statistics students, an instructor asked her students how many flip-flops they have. Suppose that the intent is to study whether there is an association between number of flip-flops and a person’s sex.