(Compound value solving for r ) At what annual rate would the following have to be invested? a. $520 to grow to $1,212.45 in 11 years b. $290 to grow to $486.36 in 6 years c. $48 to grow to $659.69 in 20 years d. $208 to grow to $278.35 in 5 years a. At what annual rate would $520 have to be invested to grow to $1,212.45 in 11 years? \% (Round to the nearest whole percent.)