A production process operates with 1% nonconforming output. Every hour a sample of 25 units of product is taken, and the number of nonconforming units counted. If one or more nonconforming units are found, the process is stopped and the quality control technician must search for the cause of nonconforming production.
a. What is the probability that 1 or more nonconforming units is found?
b. What is the probability that exactly 3 units are nonconforming?