Sean wanted to ensure that he had $75,000 for his child's university education. As soon as his child was born, he started saving $1,225 every 6 months in an investment fund. If he achieved his investment target on his child's 18th birthday, and he made no deposit on the child's 18th birthday, calculate the following: a. The nominal interest rate for the investment, compounded quarterly. b. Calculate the effective interest rate for this investment.