In a large city, the city supervisor wants to find the average number of aluminum cans that each family recycles per month. So, she surveys 19 families and finds that these 19 families recycle an average of 225 cans per month with a standard deviation of 45 cans per month. Find the 80 % confidence interval for the mean number of cans that all of the families in the city recycle per month. Answer the following questions: 1. Multiple choice: Which equation would you use to solve this problem? A . X - Z