Cigarette use with data from 1965 to 2009 the percent p of

Question

Question: Cigarette use With data from 1965 to 2009, the percent p of adults who smoke cigarettes can be modeled by the equation

p = 43.3 - 0.504t

where t is the number of years past 1960 (Source: Centers for Disease Control and Prevention).

(a) What value of t represents 2015?

(b) What percent does this equation predict for 2015?

(c) This equation ceases to be effective when p becomes negative and perhaps before that. Find the years when p < 0.