Each function described below models the specified data for the years 2006 through 2016, with t = 6 corresponding to 2006. Estimate a reasonable scale for the vertical axis (e.g., hundreds, thousands, millions, etc.) of the graph and justify your answer. (There are many correct answers.)
(a) f(t) represents the average salary of college professors.
(b) f(t) represents the U.S. population.
(c) f(t) represents the percent of the civilian workforce that is unemployed.
(d) f(t) represents the number of games a college football team wins?