That would only give you the value, with interest, of the initial $50 deposit.

you still need to add the value of the second, third, and forth year deposits with interest

and then add the amount that accumulates in the final three years of semi-annual compounding.

Abdul, a graduate student made annual deposits of $50 at the beginning of each year in his Credit Union account which pays 6% interest compounded semi-annually. After 4 years, Abdul makes no more deposits. What will the balance in the account be 3 years after the last deposit?

F= 50(1+(.06/2))^(4*2)