To control the quailty of a manufactured product, samples of the product are taken at specified inspection time periods and a quality characteristic is measured for each product. If the average measurement falls below a certain predetermined threshold, the process is declared out of control and is interrupted. The number of inspections between successive interruptions of the process is called a run length. The expected value of the random variable X = run length is called the average run length. Suppose the probability that an inspection will result in the process being interrupted is 0.01.
a) The random variable X is (choose one)
(i) Binomial (ii) Hypergeometric (iii) Negative Binomial (iv) Poisson
b) Give the sample space and pmf of X.
c) What is the average run length?