DragonSlayer. Good Try, I see what you did. But you seemed to have calculated this as Simple Interest. For this question, you need to solve it as Compound Interest. Lets start.
Let me first introduce you to the Compound Interest Formula.
Principal X (1 + Periodic Rate) ^ Number of Periods = Future Amount
Principal is the amount in the account in one yeat given that this is an annual interest.
So lets add the Principal:
$${\mathtt{35}}{\mathtt{\,\times\,}}{\mathtt{12}} = {\mathtt{420}}$$
The Principal is 420.
So lets add that in:
420 * (1 + Period rate) ^ Number of Periods. = Future Amount.
Now the period rate is 7%. So lets turn that into a decimal.
0.07. Lets place that in
420 * (1 + 0.07) ^ Number of Periods. = Future Amount.
Number of Periods is the Year.
420 * (1 + 0.07) ^ 30= Future Amount.
$${\mathtt{420}}{\mathtt{\,\times\,}}{\left({\mathtt{1}}{\mathtt{\,\small\textbf+\,}}{\mathtt{0.07}}\right)}^{{\mathtt{30}}} = {\mathtt{3\,197.147\: \!117\: \!918\: \!052\: \!266\: \!8}}$$
The amount would then be 3,197.14 Dollars.
However, providing that Money is deposited every month... I will solve it on the next post.