(Compound value solving for r ) At what annual rate would the following have to be invested? a. $520 to grow to $1,171.14 in 12 years b. $330 to grow to $657.55 in 8 years c. $52 to grow to $599.20 in 20 years d. $220 to grow to $267.41 in 4 years a. At what annual rate would $520 have to be invested to grow to $1,171.14 in 12 years? % (Round to the nearest whole percent.)