A lot consisting of 100 fuses is inspected by the following procedure: 5 fuses are selected randomly, and if all 5 "blow" at the specified amperage, the lot is accepted. Suppose that the lot contains 10 defective fuses. Find the probabily of accepting the lot.
HINT: Let X ba a r.v. equil to the number of defective fuses in the sample of 5 and the result of the r.v. X is known as the "hypergeometric" r.v. with parameters (N,r,n)
(a) Find the pmf of X.
(b) Find the mean and variance of X.