For an investment to triple in value during a $7-$year period,

a$.$ What annually compounded rate of return must it earn? $($Do not round intermediate calculations and round your final answer to $2$ decimal places.$)$

Annually compounded rate of return $\%$

b$.$ What quarterly compounded rate of return must it earn? $($Do not round intermediate calculations and round your final answer to $2$ decimal places.$)$

Quarterly compounded rate of return

$\%$

c$.$ What monthly compounded rate of return must it earn? $($Do not round intermediate calculations and round your final answer to $2$ decimal places.$)$

Monthly compounded rate of return

$\%$