SAT Mathematics Practice Test 6

The situation can be represented by the equation $\mathit{x}\left(2^4\right)=480$, where the 2 represents the fact that the amount of money in the account doubled each year and the 4 represents the fact that there are 4 years between January 1, 2001, and January 1, 2005. Simplifying $\mathit{x}\left(2^4\right)=480$ gives $16\mathit{x}=480$. Therefore, $\mathit{x}=30$.