Consider the information presented in the introductory case of this chapter. Recall that Anne wants to determine if the marketing campaign has had a lingering effect on the amount of money customers spend on iced coffee. Before the campaign, customers spent an average of $4.18 on iced coffee with a standard deviation of

$0.84. Anne reports that the average amount, based on 50 customers sampled after the campaign, is $4.26. She wants to calculate the probability that customers spend an average of $4.26 or more on iced coffee. L056