Based on Data Set 1 in Appendix B, assume that adult females have blood platelet counts that are normally distributed with a mean of 280 and a standard deviation of 65.
a. Find the probability that a randomly selected adult female has a platelet count greater than 345.
b. Find the probability that a randomly selected adult female has a platelet count between 215 and 345.
c. If 25 adult females are randomly selected, find the probability that the mean of their platelet counts is less than 319.
d. Find the value of P80, the 80th percentile.