Welcome to Westonci.ca, your ultimate destination for finding answers to a wide range of questions from experts. Get quick and reliable solutions to your questions from a community of seasoned experts on our user-friendly platform. Discover detailed answers to your questions from a wide network of experts on our comprehensive Q&A platform.

David’s bank offers a 36-month Certificate of Deposit (CD) with an APR of 2.25%. Use the compound interest formula to answer the following: a) If P = 2000, what is A(8)? b) Solve the equation A(t) = 4000 for t. c) What principal P should be invested so that the account balance is $2000 in three years?

Sagot :

Using compound interest, it is found that:

a) A(8) = 2389.66

b) t = 31.15

c) P = 1870.85

Compound interest:

[tex]A(t) = P\left(1 + \frac{r}{n}\right)^{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:

  • The APR is of 2.25%, hence [tex]r = 0.0225[/tex].
  • No information about the number of compounding per year, hence [tex]n = 1[/tex].

Item a:

[tex]P = 2000[/tex], hence:

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

[tex]A(8) = 2000\left(1 + \frac{0.0225}{1}\right)^{8}[/tex]

[tex]A(8) = 2389.66[/tex]

Item b:

[tex]A(t) = 4000[/tex], hence:

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

[tex]4000 = 2000\left(1 + \frac{0.0225}{1}\right)^{t}[/tex]

[tex](1.0225)^t = 2[/tex]

[tex]\log{(1.0225)^t} = \log{2}[/tex]

[tex]t\log{1.0225} = \log{2}[/tex]

[tex]t = \frac{\log{2}}{\log{1.0225}}[/tex]

[tex]t = 31.15[/tex]

Item c:

[tex]A(3) = 2000[/tex], hence:

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

[tex]2000 = P\left(1 + \frac{0.0225}{1}\right)^{3}[/tex]

[tex]P = \frac{2000}{(1.0225)^3}[/tex]

[tex]P = 1870.85[/tex]

A similar problem is given at https://brainly.com/question/24850750