An investment firm advertises certificates of deposit paying a $6\mathrm{.}4\%$ effective rate. Find the annual nominal rate, compounded weekly, that gives the effective rate.

Part $1$ of $4$

$($a$.)$ Identify the formula needed to solve the given finance problem with the information given.

A$.I=Prt$

B$.A=P(1+rt)$

C$.A=P(1+i{)}^n,i=\frac{r}{m},n=mt$

D$.r_{\text{e}\text{f}\text{f}}=(1+\frac{r}{m}{)}^m-1$

E$.r_{\text{e}\text{f}\text{f}}=(\frac{A}{P}{)}^{\frac{1}{t}}-1$

Part $2$ of $4$

$($b$.)$ Which variable in Formula $D$ are we solving for?

Part $3$ of $4$

$($c$.)$ Fill in the formula and solve.

$064(1+\frac{r}{5252}{)}^{52}52$

Part $4$ of $4$

$($d$.)$ What is the final answer? Round your final answer to two decimal places.

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