Some 213.9 million pounds of fireworks were used in the United States in 2009, and that amount decreased by about 20.1 million pounds per year until 2013 (Source: American Pyrotechnics Association). Let F be the amount (in millions of pounds) of fireworks used in the year that is t years since 2009.
a. Find an equation of a linear model to describe the situation.
b. Use the equation you found in part (a) to estimate in which year 150 million pounds of fireworks were used.
c. Solve the equation you found in part (a) for t.
d. Use the equation you found in part (c) to estimate in which year 150 million pounds of fireworks were used.
e. Compare the results you found in parts (b) and (d). Which equation was easier to use? Explain.