You are trying to calculate the Future Value of $30,627.78. But notice that the interest rate is 70%, the way you have it written!! I think that it is more likely that you meant 7%. So, I will calculate it at 7% as follows: $30,627.78 (1+0.07/12)^12*30
FV =$30,627.78(1 + 0.0058333...)^360
FV =$30,627.78 x 8.116497475.....
FV =$248,590.30
