For the business administration My question is An investment of $$16,000$ is growing at $3\%$ compounded quarterly.

a$.$ Calculate the accumulated amount of this investment at the end of year $1.$

Round to the nearest cent

b$.$ If the interest rate changed to $4\%$ compounded monthly at the end of year $1,$ calculate the accumulated amount of this investment at the end of year $4.$

Round to the nearest cent

$($c$)$ Calculate the amount of interest earned from this investment during the $4-$ year period.