Answer: (a) [tex]\bold{A=900\bigg(1+\dfrac{0.07}{4}\bigg)^{4t}}[/tex]
(b) A = $1680.67
(c) t = 9.99 years
(d) A = $1689.85
Step-by-step explanation:
[tex]A=P\bigg(1+\dfrac{r}{n}\bigg)^{nt}[/tex] where
- A is the amount accrued (balance)
- P is the principal (original/initial amount)
- r is the interest rate (convert to a decimal)
- n is the number of times compounded per year
- t is the number of years
a) Given: P = 900, r = 7% = 0.07, n = quarterly = 4
[tex]\bold{A=900\bigg(1+\dfrac{0.07}{4}\bigg)^{4t}}[/tex]
b) Given: P = 900, r = 7% = 0.07, n = quarterly = 4, t = 9
[tex]A=900\bigg(1+\dfrac{0.07}{4}\bigg)^{4(9)}\\\\\\A = 900\bigg(1+\dfrac{0.07}{4}\bigg)^{36}[/tex]
A = 1680.67
c) Given: A = 1800, P = 900, r = 7% = 0.07, n = quarterly = 4
[tex]1800=900\bigg(1+\dfrac{0.07}{4}\bigg)^{4t}\\\\\\2=\bigg(1+\dfrac{0.07}{4}\bigg)^{4t}\\\\\\ln\ 2=ln\bigg(1+\dfrac{0.07}{4}\bigg)^{4t}\\\\\\ln\ 2 = 4t\ ln\bigg(1+\dfrac{0.07}{4}\bigg)\\\\\\\dfrac{ln\ 2}{4\ ln\bigg(1+\dfrac{0.07}{4}\bigg)}=t\\\\\\\bold{t=9.99}[/tex]
d) [tex]A=Pe^{rt}[/tex]
Given: P = 900, r = 7% = 0.07, t = 9
[tex]A=900e^{0.07(9)}\\\\\\A=900e^{.63}\\\\\\\bold{A=1689.85}[/tex]
