Question: Candy is in charge of her school’s “Math Appreciation Week”, and she is wondering if attendance is up at the events this year. She randomly selects some sessions from this year, and determines the number of people at each session, given below. She also selects some sessions from last year, for a comparison.

This year: 22, 32, 27, 28, 45, 50, 39, 23, 36, 44, 41, 29, 35

Last year: 18, 22, 30, 40, 29, 35, 26, 24, 15, 19

You may assume both sets of data are normally distributed. Construct a 95% confidence interval for the mean difference between the two groups. Can Candy conclude that attendance (per session) is higher this year than last year?