Suppose that the service life, in years of a hearing air batter, is a random variable having a weibull distribution with the scale parameter = 5.0 and that shape parameter = 4
a. What is the probability the battery will fail between the third and fourth year?
b. What time is the life-time which 85% of the batteries would have failed?
c. What is the hazard rate right after the first two years of operation?