$4.$ Given the following data and an interest rate of $18\mathrm{.}2\%$

Year Amount

$0$ $$(16,447)$

$1$ $$5,000$

$2$ $$7,000$

$3$ $$4,000$

$4$ $$10,000$

a$.$ Find the present value of the cash flows $(5)$

b$.$ Find the future value of the cash flows in year $15.(5)$