Assume that the life of a roller bearing follows a Weibull distribution with parameters ß = 2 and d = 10,000 hours.
a) Determine the probability that a bearing lasts at least 8000 hours.
b) Determine the mean time until failure of a bearing.
c) If 10 bearings are in use and failures occur independently, what is the probability that all 10 bearings last at least 8000 hours?