B Your grandmother invested one lump sum 17 years ago at 4.25 percent interest. Today, she gave you the proceeds of that investment which totaled $5,539.92. How much did your grandmother originally invest? $2,700.00 $2,730.30 $2,750.00 $2,768.40 $2,774.90 Forty years ago, your father invested $2,500. Today that investment is worth $107,921. What is the average rate of return your father earned on his investment?