Answer:
The annual interest rate would have to be of 0.1%.
Step-by-step explanation:
Compound interest:
The compound interest formula is given by:
[tex]A(t) = P(1 + \frac{r}{n})^{nt}[/tex]
Where 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 and t is the time in years for which the money is invested or borrowed.
Jerod hopes to earn $1200 in interest in 4.9 years time from $24,000 that he has available to invest.
This means that:
[tex]A(4.9) = 1200 + 24000 = 25200[/tex]
[tex]t = 4.9[/tex]
[tex]P = 24000[/tex]
Compounded monthly:
This means that [tex]n = 12[/tex]
What would the annual rate of interest have to be?
We have to solve for r, so:
[tex]A(t) = P(1 + \frac{r}{n})^{nt}[/tex]
[tex]25200 = 24000(1 + \frac{r}{12})^{12*4.9}[/tex]
[tex](1 + \frac{r}{12})^{12*4.9} = \frac{25200}{24000}[/tex]
[tex](1 + \frac{r}{12})^{58.8} = 1.05[/tex]
[tex]\sqrt[58.8]{(1 + \frac{r}{12})^{58.8}} = \sqrt[58.8]{1.05}[/tex]
[tex]1 + \frac{r}{12} = (1.05)^{\frac{1}{58.8}}[/tex]
[tex]1 + \frac{r}{12} = 1.00083[/tex]
[tex]\frac{r}{12} = 0.00083[/tex]
[tex]r = 12*0.00083[/tex]
[tex]r = 0.001 [/tex]
The annual interest rate would have to be of 0.1%.