Chapter 2, Problem 97RE

Medicare. The annual expenditures for Medicare (in billions of dollars) by the U.S. government for selected years since $1980$ are shown in Table $5$. Let $x$ represent years since $1980$.

(A) Find an exponential regression model $\left(y=a{b}^x\right)$ for the data. Estimate (to the nearest billion) the annual expenditures in $2025$.

(B) When will the annual expenditures exceed two trillion dollars?