If 6000 dollars is invested in a bank account at an interest rate of 5 per cent per year, determine each of the following. Round each answer to the nearest cent.

a) Find the amount in the bank after 7 years if interest is compounded annually
b) Find the amount in the bank after 7 years if interest is compounded quarterly
c) Find the amount in the bank after 7 years if interest is compounded monthly
d) Finally, find the amount in the bank after 7 years if interest is compounded continuously