1. Suppose one performs the following acceptance sampling scheme. From a lot of N light bulbs (N is a large number), 100 bulbs are sampled at random without replacement and tested. The probability that a bulb is defective is 0.1, and the lot is accepted if no more than 15 defective bulbs are found in the sample. Find an approximation (using the continuity correction) for the probability that the lot is accepted.
2. Customers arrive at a queue according to a Poisson process with an average arrival rate of 4 per hour.
(a) Find the probability of exactly three arrivals in 1 hour.
(b) Find the probability of at least three arrivals in 2 hours.
(c) Use the normal distribution to approximate the probability in part (a).