answer both questions please

The force of interest is 87 0.08t2 + 0.035. An initial deposit of $4000 is made into an account at time 0, and $4000 is withdrew at time 4. What is the account value (up to $0.01) at time 5? Fund 1 earns a nominal interest of 7.50% convertible semiannually, while the rate of discount for Fund 2 is 6.75% compounded semiannually. The equivalent force of interest for Fund 1 (Fund 2, respecitvely) is denoted as 81 (82, respectively). Calculate 81/82 (use 4 decimal places)