Fredo deposits $75 a year in an account earning 3% interest compounded annual. if he deposits $75 a year and does not make any withdrawals, how much interest will the account earn in the fourth year?
Total = principal (1+rate)^years
Total = 75 (1.03)^4 =
84.41 = 9.41 Interest
Total = 75 (1.03)^3 =
81.95 = 6.95 Interest
Total = 75 (1.03)^2 = 79.57
= 4.57 Interest
Total = 75 * (1.03)^1 = 77.25
= 2.25 Interest
Four Years of Interest = $23.18
The interest the account will earn in the fourth year is:
$ 9.4132
We know that the amount obtained on a account if the interest is compounded annually is given by:
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where P is the principal amount.
r is the rate at which the interest is calculated in decimal form.
t is the time i.e. number of years.
and A is the amount after t years.
Hence, the interest obtained is:
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Here we are given :
P=$ 75
r= 0.03
and we are asked to calculate the interest when t= 4 .
Hence, we have:
\(A=75(1+0.03)^4\\\\A=75(1.03)^4\\\\A=84.4132\)
Hence,
\(\text{Interest obtained}=84.4132-75\\\\\text{Interest obtained}=\$ 9.4132\)