Assume that the life of a roller bearing follows a Weibull distribution with parameters 2 and 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