20% of memory chips made in certain plant are defective. Find the probability that in a lot of 100 randomly chosen for inspection.
i) atmost 15 will be defective
ii) exactly 15 will be defective
Obtain these probability also by using Normal Approximation to binomial probabilities.
The number of defectives in the batch has a binomial distribution (no approximations at this point).
The approximation you are asked to use is the normal approximation to the binomial. Where is approximated as .