Answer:
4594.76 USD will be in the account on Burt's 18th birthday.
Step-by-step explanation:
Since interest rate is constant in time, we can use the definition of composite interest to determine how much money will be on Burt's 18th birthday, that is:
[tex]C = C_{o}\cdot \left(1+\frac{r}{100} \right)^{t}[/tex] (1)
Where:
[tex]C_{o}[/tex] - Initial amount, measured in US dollars.
[tex]C[/tex] - Current amount, measured in US dollars.
[tex]r[/tex] - Annual interest rate, measured in percentage.
[tex]t[/tex] - Time, measured in years.
If we know that [tex]C_{o} = 1250\,USD[/tex], [tex]r = 7.5[/tex] and [tex]t = 18[/tex], then the money in the savings account on Burt's 18th birthday is:
[tex]C = (1250\,USD)\cdot \left(1+\frac{7.5}{100} \right)^{18}[/tex]
[tex]C = 4594.76\,USD[/tex]
4594.76 USD will be in the account on Burt's 18th birthday.