Given is the Principal amount, P = 1600 dollars. 
Given the Annual interest is 7% i.e. r = 0.07 
Given the Compounding period is semi-annually i.e. n = 2. 
Given is the Time of investment, t = 33 years. 
It says to find the Final Value of invested amount in the account after 33 years. 
We know the formula for Future Value of Money is given as follows :- 

Hence, the final balance would be 15,494.70 dollars.