A woman deposits [tex]$\$[/tex]14,000[tex]$ at the end of each year for 13 years in an investment account with a guaranteed interest rate of $[/tex]5\%[tex]$ compounded annually.

(a) Find the value in the account at the end of the 13 years.

(b) Her sister works for an investment firm that pays $[/tex]4\%[tex]$ compounded annually. If the woman deposits money with this firm instead of the one in part (a), how much will she have in her account at the end of 13 years?

(c) How much would she lose or gain over 13 years by investing in her sister's firm?

(a) The woman's deposits form an ordinary annuity because the deposits are made at the end of each period. Therefore, the formula
\[
FV = PMT \left[\frac{(1+i)^n - 1}{i}\right]
\]
should be used. The value in the account at the end of the 13 years will be $[/tex]\[tex]$247,981.76$[/tex].
(Do not round until the final answer. Then round to the nearest cent as needed.)

(b) She will have a total of [tex]$\$[/tex]\square$ in her account at her sister's firm at the end of 13 years.
(Do not round until the final answer. Then round to the nearest cent as needed.)

(c) How much would she lose or gain over 13 years by investing in her sister's firm?



Answer :

Sure! Let’s break down the given question into parts (a), (b), and (c) and find the relevant solutions for each part.

### Part (a):
We need to find the future value of an annuity where the woman is depositing [tex]$\$[/tex]14,000[tex]$ at the end of each year for 13 years in an account that has an interest rate of \(5\%\) compounded annually. The formula for the future value of an ordinary annuity is: \[ FV = PMT \left[\frac{(1 + i)^n - 1}{i}\right] \] where: - \(PMT\) is the annual payment (deposit), - \(i\) is the annual interest rate, and - \(n\) is the number of periods (years). Substitute the given values into the formula: - \(PMT = 14,000\), - \(i = 0.05\), - \(n = 13\). \[ FV = 14000 \left[\frac{(1 + 0.05)^{13} - 1}{0.05}\right] \] After evaluating this expression, we find: \[ FV = \$[/tex]247,981.76
\]
Thus, the value in the account at the end of 13 years will be [tex]$\$[/tex]247,981.76[tex]$. ### Part (b): Now, we need to find the future value if the woman deposits the same amount (\$[/tex]14,000) at the end of each year for 13 years, but this time the investment firm pays [tex]\(4\%\)[/tex] compounded annually.

Using the same future value formula for an ordinary annuity:
[tex]\[ FV = PMT \left[\frac{(1 + i)^n - 1}{i}\right] \][/tex]

Substitute the new interest rate:
- [tex]\(PMT = 14,000\)[/tex],
- [tex]\(i = 0.04\)[/tex],
- [tex]\(n = 13\)[/tex].

[tex]\[ FV = 14000 \left[\frac{(1 + 0.04)^{13} - 1}{0.04}\right] \][/tex]
After evaluating this expression, we find:

[tex]\[ FV = \$232,775.73 \][/tex]
Therefore, at her sister’s firm, she will have [tex]$\$[/tex]232,775.73[tex]$ in her account at the end of 13 years. ### Part (c): Finally, we need to calculate the gain or loss if the woman invests in her sister’s firm compared to the first investment firm. The gain or loss is determined by: \[ \text{Gain/Loss} = FV_{\text{sister's firm}} - FV_{\text{first firm}} \] From parts (a) and (b): - \(FV_{\text{first firm}} = \$[/tex]247,981.76\),
- [tex]\(FV_{\text{sister's firm}} = \$232,775.73\)[/tex].

Therefore:
[tex]\[ \text{Gain/Loss} = 232,775.73 - 247,981.76 = -\$15,206.03 \][/tex]

This means she would lose [tex]$\$[/tex]15,206.03[tex]$ over the 13 years by investing in her sister’s firm compared to the first investment firm. Conclusively, her outcomes are: (a) Value in the first firm after 13 years: $[/tex]247,981.76[tex]$. (b) Value in her sister's firm after 13 years: $[/tex]232,775.73[tex]$. (c) Loss over 13 years by investing in her sister's firm: $[/tex]15,206.03$.