AnnoyCo, a large consumer products firm, has recently introduced a new product. As part of the launch, 25% of the customers in the company's database received calls from AnnoyCo's telemarketers.
It is now one year after the launch of the product. 40% of the customers in the company's database have purchased the product.
A recent survey by the company's marketing department has determined that among customers who have bought the product, one of eight were called.
(a) What is the probability that a customer chosen at random from the company's data base has bought the product?
(b) What is the probability that this customer was called and bought the product?
(c) Given that the customer was called, what is the probability he or she bought the product?
(d) Did telemarketing help the company's sales? Explain in a sentence or two.