Sepia Inc. issued $475,000 bonds that were redeemable in 7 years. They established a sinking fund that was earning 5.25% compounded semi-annually to pay back the principal of the bonds on maturity. Deposits were being made into the fund at the end of every 6 months.

a. Calculate the size of the periodic sinking fund deposits.

b. Calculate the sinking fund balance at the end of the 4th payment period.

c. Calculate the amount of interest earned during the 5th payment period.

d. Calculate the amount by which the sinking fund increased in the 5th payment period.