Answer:
Javier deposited $178.79 initially
Step-by-step explanation:
Compound Interest
It occurs when the interest is reinvested rather than paying it out. It's basically earning interest over interest.
The formula is:
[tex]{\displaystyle A=P\left(1+{\frac {r}{n}}\right)^{nt}}[/tex]
Where:
A = final amount
P = initial principal balance
r = interest rate
n = number of times interest applied per time period
t = number of time periods elapsed
If the final amount is known, we can solve for the principal:
[tex]{\displaystyle P=A\left(1+{\frac {r}{n}}\right)^{-nt}}[/tex]
Javier opened a savings account t=5 years ago. The account has an interest rate of r=3%= 0.03 compounded quarterly. Since there are 4 quarters in a year, n=4. The current balance is A=$200. Let's calculate the initial balance or principal:
[tex]{\displaystyle P=\$200\left(1+{\frac {0.03}{4}}\right)^{-3*5}}[/tex]
[tex]{\displaystyle P=\$200(1.0075)^{-15}}[/tex]
[tex]{\displaystyle P=\$200*0.894}[/tex]
[tex]\boxed{P =\$178.79}[/tex]
Javier deposited $178.79 initially