a$.$ If you take out an $$41,500$ car loan that calls for $48$ monthly payments starting after $1$ month at an APR of $13\mathrm{.}40\%,$ what is your monthly payment? $($Do not round intermediate calculations. Round your answer to $2$ decimal places.$)$

Monthly payment

$

b$.$ What is the effective annual interest rate on the loan? $($Do not round intermediate calculations. Round your answer to $2$ decimal places.$)$

Effective annual interest rate $\%$