$($Compound value solving for $r)$ At what annual rate would the following have to be invested?

a$.$ At what annual rate would $$520$ have to be invested to grow to $$1,253\mathrm{.}12$ in $13$ years?

b$.$ $$330$ to grow to $$657\mathrm{.}55$ in $8$ years?

c$.$ $$51$ to grow to $$370\mathrm{.}43$ in $19$ years?

d$.$ $$200$ to grow to $$253\mathrm{.}06$ in $6$ years?

$($Round to the nearest whole percent.$)$