We have the following:
The formula for compound interest is as follows
[tex]\begin{gathered} A=P(1+r)^t \\ \end{gathered}[/tex]A is amount (current balance 400), P is the principal ( deposit initially), r is the rate (0.07) and is the time ( 7 years)
replacing:
[tex]\begin{gathered} 400=P(1+0.07)^{7^{}} \\ P=\frac{400}{(1.07)^7} \\ P=249.09 \end{gathered}[/tex]Which means that the initial deposit was $ 249.09
