Answer
$y=6200(1.007)^{12t}$.
Work Step by Step
The given values are
Initial amount $P=\$6200$.
Rate of interest $r=8.4\%=0.084$.
Number of time interest is compounded per year.
$n=12$.
Formula for the compound interest
$\Rightarrow y=P(1+\frac{r}{n})^{nt}$
Substitute all the values.
$\Rightarrow y=6200(1+\frac{0.084}{12})^{12t}$
Simplify.
$\Rightarrow y=6200(1+0.007)^{12t}$
$\Rightarrow y=6200(1.007)^{12t}$.
