Five years ago, the hair dryer produced by the Wilson Appliance Company accounted for 50 percent of all sales of hair dryers nationwide  Currently, however, Wilson Appliance' s product makes up only 25 percent of such sales
Because of this decline, and because the average net income that Wilson receives per hair dryer sold has not changed over the last 5 years, the company' s net income from sales of the product must be only half of what it was 5 years ago
overlooks the possibility that the retail price of Wilson Appliance's hair dryer may have increased over the past 5 years