The formula for interest compounded continuously is:
[tex]P_t(cont)=P_0\cdot e^{r\cdot t}.[/tex]
The formula for the compound in periods:
[tex]P_t(period)=P_0\cdot(1+\frac{r}{n})^{n\cdot t}\text{.}[/tex]
Where:
• P_t is the amount of money after t years,
,
• P_0 is the initial amount of money,
,
• r is the ratio in decimal form,
,
• n is the number of compounded periods per year,
,
• t is the number of years.
We must compute the amount of money of an investment with:
• P_0 = $10,000,
,
• r = 5% = 0.05,
,
• t = 4 years.
a) Compounded semiannually
We use the second formula with n = 2:
[tex]P_4(semi)=\text{ \$10,000 }\cdot(1+\frac{0.05}{2})^{2\cdot4}\cong\text{ \$12,184.}03.[/tex]
b) Compounded quarterly
We use the second formula with n = 4:
[tex]P_4(quart)=\text{ \$10,000 }\cdot(1+\frac{0.05}{4})^{4\cdot4}\cong\text{ \$12,198.90.}[/tex]
c) Compounded monthly
We use the second formula with n = 12:
[tex]P_4(monthly)=\text{ \$10,000 }\cdot(1+\frac{0.05}{12})^{12\cdot4}\cong\text{ \$12,}208.95.[/tex]
d) Compounded continuously
We use the first formula:
[tex]P_4(cont)=\text{ \$10,000 }\cdot e^{0.05\cdot4}=\text{ \$12,}214.03.[/tex]
Answer
a) Compounded semiannually: $12,184.03
b) Compounded quarterly: $12,198.90
c) Compounded monthly: $12,208.95
d) Compounded continuously: $12,214.03