Consider a $$5,000,000,8\mathrm{.}5\%$ APR, $30-$year mortgage with monthly payments, and expected realistic prepayment horizon of $7$ years. What is the contractual yield $($effective interest rate$)$ at issuance over the expected life of the loan under the following circumstances:

Please answer using excel

No points or penalties

One point of discount

Three points of discount

Three points of discount plus one point of prepayment penalty.