A production process is set to produce n items in a single run. The long run average of defective

items produced in a run is 7 and variance 2.1. Calculate

(a) the number of total items n produced in a single run,

(b) the probability p of producing a defective item in a single run,

(c) the probability that 4 defective items are produced in a single run,

(d) the probability that more than 8 defective items are produced in a single run,

(e) the probability that we have to check exactly 4 items to nd a defective item.