Rachel deposited $6,449.82 into a savings account with an interest of 6.9% compounded annually. About how long will it take for the accout to be worth $8,000?

Rachel deposited 644982 into a savings account with an interest of 69 compounded annually About how long will it take for the accout to be worth 8000 class=

Respuesta :

Answer:

3 years and 3 months.

Step-by-step explanation:

Since, the amount formula in compound interest,

[tex]A= P(1+\frac{r}{100})^t[/tex]

Where,

P = principal amount,

r = rate per period,

t = number of periods,

Here, A = $ 8,000, r = 6.9%, P = $6,449.82,

By substituting the values,

[tex]8000 = 6449.82(1+\frac{6.9}{100})^t[/tex]

[tex]\frac{8000}{6449.82}=(1+\frac{6.9}{100})^t[/tex]

[tex]\ln (\frac{8000}{6449.82})=t\ln(1.069)[/tex]

[tex]\implies t = \frac{\ln (\frac{8000}{6449.82})}{\ln(1.069)}=3.228[/tex]

Hence, it would be take 3.228 years or 3 years and 3 months.