Karen obtained a $$36,000$ loan at $3\mathrm{.}5\%$ compounded semiannually.

a$-1.$ What monthly payment will repay the loan in $81/2$ years? $($Do not round intermediate calculations and round your final answer to $2$ decimal places.$)$

Monthly payment $

a$-2.$ How much interest will Karen pay over the life of the loan? $($Round intermediate calculations to $2$ decimal places and round your final answer to the nearest dollar.$)$

Total interest $