Each salesperson in a large department store chain is rated on his or her sales ability and potential for advancement. The data for the 500 sampled salespeople are summarized in the following table.

	Potential for Advancement
Fair	Good	Excellent
Sales ability	Below average	22	18	28
Average	48	66	56
	Above average	87	66	109

What is the probability that a salesperson selected at random will have an excellent potential for advancement given he or she also has average sales ability?

Select one:

a. 0.46

b. 0.22

c. 0.42

d. 0.33