Suppose that $3000 is placed in a savings account at an annual rate of 3.6%, compounded monthly. Assuming that no withdrawals are made, how long will it take for the account to grow to $4500? Do not round any intermediate computations, and round your answer to the nearest hundredth.

Respuesta :

Using compound interest, it is found that it will take 11.28 years for the the account to grow to $4500.

The compound interest formula is given by:

[tex]A(t) = P(1 + \frac{r}{n})^{nt}[/tex]

A(t) is the amount of money after t years.

P is the principal(the initial sum of money).

r is the interest rate(as a decimal value).

n is the number of times that interest is compounded per year.

t is the time in years for which the money is invested or borrowed.

In this problem:

  • $3000 is placed in the account, thus [tex]P = 3000[/tex].
  • Interest rate of 3.6%, thus [tex]r = 0.036[/tex].
  • Monthly compounding, thus [tex]n = 12[/tex].

We have to solve for t when [tex]A(t) = 4500[/tex], thus:

[tex]A(t) = P(1 + \frac{r}{n})^{nt}[/tex]

[tex]4500 = 3000(1 + \frac{0.036}{12})^{12t}[/tex]

[tex](1.003)^{12t} = 1.5[/tex]

[tex]\log{(1.003)^{12t}} = \log{1.5}[/tex]

[tex]12t\log{1.003} = \log{1.5}[/tex]

[tex]t = \frac{\log{1.5}}{12\log{1.003}}[/tex]

[tex]t = 11.28[/tex]

It will take 11.28 years for the the account to grow to $4500.

A similar problem is given at https://brainly.com/question/24507395