Question 8 [14 marks] The lifetimes of interactive computer chips produced by a certain semiconductor manufacturer are normally distributed having mean 4.4 10^6 hours with a standard deviation of 3 10^5 hours. a) If a mainframe manufacturer requires that at least 90 percent of the chips from a large batch will have lifetimes of at least 4.0 10^6 hours, should he contract with the semiconductor firm? b) What is the probability that a batch of 100 chips will contain at least 4 whose lifetimes are less than 3.8 10^6 hours?