For this exercise, round all regression parameters to three decimal places. The following table shows national health care costs, measured in billions of dollars.

Date	1970	1980	1990	2000	2010
Costs in billions	75	253	714	1353	2570

(a) Plot the data. (Let t be years since 1970 and H the costs in billions of dollars.)

(b) Find an exponential function that approximates the data for health care costs. (Let t be years since 1970 and H the costs in billions of dollars.)

A) H = 72.438 1.143^t

B) H = 3120.372 0.916^t

C) H = 993.002 1.002^t

D) H = 94.414 1.091^t

E) H = 2560.371 0.872^t

(c) By what percent per year were national health care costs increasing during the period from 1970 through 2010? (Use the model found in part (b). Round your answer to one decimal place.) ____% (d) Use functional notation to express how much money was spent on health care in the year 2013. (Let t be years since 1970.)

H(_____) Estimate that value. (Use the model found in part (b). Round your answer to the nearest integer.) _____ billion dollars