Use the following formula.

$A=\frac{P[(1+\frac{r}{n}{)}^{nt}-1]}{(\frac{r}{n})}$

Suppose that you drive $40,000$ miles per year and gas averages $$4$ per gallon. Complete parts a$.$ and b$.$ below.

a$.$ What will you save in annual fuel expenses by owning a hybrid car averaging $40$ miles per gallon rather than an SUV averaging $16$ miles per gallon?

$ $6,000$

$($Round to the nearest dollar as needed.$)$

b$.$ If you deposit your monthly fuel savings at the end of each month into an annuity that pays $4\mathrm{.}8\%$ compounded monthly, how much will have saved at the end of nine years?

$

$($Round to the nearest dollar as needed.$)$