The life spans of a species of fruit fly have abell-shaped distribution, with a mean of 33 days and a standard deviation of 4 days.

(a) The life spans of three randomly selected fruit flies are 34 days, 31 days, and 45 days. Find the z-score that corresponds to each life span. Determine whether any of these life spans are unusual.

(b) The life spans of three randomly selected fruit flies are 29 days, 25 days, and 45 days. Using the Empirical Rule, find the percentile that corresponds to each life span.