The life spans of a species of lady bugs have a bell-shaped distribution, with a mean of 1000 days and a standard deviation of 100 days.

(a) The life spans of three randomly selected lady bugs are 1250 days, 1175 days, and 950 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 lady bugs are 1150 days, 910 days, and 845 days. Using the Empirical Rule, find the percentile that corresponds to each life span.