The Rise and Fall of D and E The graph indicates that vitamin D sales increased from

Chapter 3, Problem 94

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The Rise and Fall of D and E The graph indicates that vitamin D sales increased from 2001 to 2009, a period during which several studies linked it to various health benefits. News that vitamin E might increase the risk of illness and death resulted in decreasing sales for the same period. $900 $750 $600 $450 $300 Sales (millions of dollars) Sales of Vitamin D and Vitamin E 2001 2009 336 425 771 40 $150 Vitamin D Vitamin E Year Source: Nutrition Business Journal In 2001, vitamin D sales were $40 million. For the period shown, sales increased by an average of $48 million per year. In 2001, vitamin E sales were $771 million, decreasing by an average of $54 million per year. a. Write a function that models the sale of vitamin D, in millions of dollars, x years after 2001. b. Write a function that models the sale of vitamin E, in millions of dollars, x years after 2001. c. In which year, to the nearest whole year, were sales of vitamin D and vitamin E the same?