Suppose the lifetime in months of an eclzigine~ working under hazardous conditions, has a Gamma distribution with a mean of 5 months and a variance of 1|] months squared. [a] Determine the median lifetime of an engine. [b] Suppose such an engine is termed successful if its lifetime exceeds 1|] months. In a sample of 10 engines1 determine the probability of at least 2 successful engines