An investigation of past consumer surveys done by a company reveals that 2/3 of customers contacted respond to the survey. The marketing manager wants to do a new survey and plans to contact 198 customers.
(a) How many responses should the manager expect to receive?
(b) Give an approximation of the probability that 140 or more customers will respond.
(c) Give an approximation of the probability that 135 to 150 customers will respond.
(d) Give an approximation of the probability that 130 or less customers will respond.
(e) Compare your approximate answers with the exact probability values obtained on Excel.