Answer
$\$ 349,496.41$
Work Step by Step
Let us consider that $P$ is defined as the deposit in dollars made at the end of each payment period for annuity, when a person pays $i$ percent interest per payment period.
The formula for amount $A$ of the annuity after $n$ deposits can be written as: $ A=P\cdot\dfrac{(1+i)^{n}-1}{i}$
We are given that $P=100 \\ n=360 \\ i=\dfrac{0.12}{12}=0.01$
Therefore, $A=100\cdot \dfrac{(1.01)^{360}-1}{0.01}\approx \$ 349,496.41$.