Sue decides to start saving money for a new car. She knows she can invest money into an account which will earn 7.5% APR, compounded monthly, and would like to have saved $15,000 after 6 years. How much money will she need to invest into the account now so that she has $15,000 after 6 years?Determine the APY (Annual Percent Yield) for the account. Determine the 6-year percent change for the account.

Respuesta :

Given:

The rate of interest is, r = 7.5% = 0.075.

The required total amount is, A = $15,000.

The number of years, t = 6 years.

The objective is to find the principal amount required to invest.

Explanation:

The general formula of compound interest is,

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

Here, n represents the number of times the interest is compounded.

It is given that the interest is compounded monthly, so the value of n = 12.

To find principal amount:

Substitute the given values in the above formula.

[tex]\begin{gathered} 15000=P(1+\frac{0.075}{12})^{12(6)} \\ P=\frac{15000}{(1+0.00625)^{72}} \\ P=9577.83 \end{gathered}[/tex]

To find APY:

The annual principal yield can be calculated as,

[tex]\begin{gathered} \text{APY}=(1+\frac{r}{n})^n-1 \\ =(1+\frac{0.075}{12})^{12}-1 \\ =0.0776 \end{gathered}[/tex]

To find percent change:

The percent change can be calculated as,

[tex]\begin{gathered} \text{\%change}=\frac{A-P}{P}\times100 \\ =\frac{15000-9577.83}{9577.83}\times100 \\ =\frac{5422.17}{9577.83}\times100 \\ =0.5661167\ldots.\times100 \\ =56.61\text{ \%} \end{gathered}[/tex]

Hence,

The principal money to be invested in the account is $ 9577.83.

The Annual Percent Yield is 0.0776.

The percent change for 6 year is 56.6%.