Suppose that the probability function in Table 11.13 reflects the possible lifetimes (in months after emergence) for fruit flies.

Table 11.13

(a) What proportion of fruit flies die in their second month?

(b) What is the probability that a fruit fly lives more than four months?

(c) What is the mean lifetime for a fruit fly?

(d) What is the standard deviation of fruit fly lifetimes?

4 p(x) 0.30 0.20 0.15 0.10 0.05