Question

Maile deposited $9,000 into a retirement account whose balance grew 4% per year. She made no further deposits or withdrawals.Which equation calculates A, the account balance, after 7 years?

Answer 1

The rule of the interest is

`A=P(1+r)^t`

Where:

A is the new amount

P is the initial amount

r is the interest rate in decimal

t is the time

Since Maile deposited $9000, then

P = 9000

Since the balance grew 4% per year, then

r = 4/100 = 0.04

Since the balance is for 7 years, then

t = 7

Substitute them in the rule above

`\begin{gathered} A=9000(1+0.04)^7 \\ A=9000(1.04)^7 \\ A=9000.1.04^7 \end{gathered}`

The correct answer is C