4-21 CanAm Financial offers investments that pay 12 percent interest compounded monthly, whereas UniMex Financial offers investments that pay 12.25 percent interest compounded semiannually. Which investment offers the better effective annual return? 4-22 Yolanda's bank advertises a savings investment that pays 6 percent compounded monthly. What is the investment's (a) annual percentage rate (APR) and (b) effective annual rate (TEAR)? 4-23 William recently graduated from NFA University, While at NFA, William took out a $50,000 student loan. His loan requires him to make monthly pay- ments for a 10-year period. (a) If the simple annual interest is 4.2 percent, what are William's monthly payments? (b) To the nearest dollar, how much will William owe on his student loan after he makes payments for three years? 4-24 When Sarah Jean purchased her house 12 years ago, she took out a 30-year mortgage for $220,000. The mortgage has a fixed interest rate of 6 percent compounded monthly. (a) Compute Sarah Jean's monthly mortgage payments.(b) If Sarah Jean wants to pay off her mortgage today, for how much should she write a check? She made her most recent mort- gage payment earlier today. 4-25 Nona purchased a new car earlier today for $32,000. She financed the entire amount using a five-year loan with a 3 percent interest rate (compounded monthly). (a) Compute the monthly payments for the loan. (b) How much will Nona owe on the loan after she makes payments for two years (i.e., after 24 payments)