To determine the amount in May's account after 10 years with her investment compounded yearly at a 9% interest rate, we can use the formula provided:
\[ a(t) = 1000(1.09)^t \]
where:
- \( a(t) \) is the amount in the account after \( t \) years,
- 1000 is the initial investment,
- 1.09 is the factor representing the original investment plus the interest rate,
- \( t \) is the number of years.
Now, substituting \( t = 10 \) into the formula:
\[ a(10) = 1000(1.09)^{10} \]
Now, we need to calculate \( (1.09)^{10} \):
\[ (1.09)^{10} \approx 2.36736 \]
Now, plug this back into the equation:
\[ a(10) = 1000 \times 2.36736 \approx 2367.36 \]
So, the amount in May's account after 10 years will be approximately $2367.36.