To calculate the earnings from a simple interest savings plan, you can use the formula:
\[ \text{Interest} = P \times r \times t \]
where:
- \( P \) is the principal amount (initial deposit),
- \( r \) is the annual interest rate (as a decimal),
- \( t \) is the time in years.
In this case:
- \( P = 800 \) (the amount deposited),
- \( r = 0.15 \) (the interest rate of 15% expressed as a decimal),
- \( t = 4 \) (the number of years the money is invested).
Plug these values into the formula:
\[ \text{Interest} = 800 \times 0.15 \times 4 \] \[ \text{Interest} = 800 \times 0.15 = 120 \] \[ \text{Interest} = 120 \times 4 = 480 \]
After 4 years, the student will have earned $480 in interest.
To find the total amount in the account after 4 years, add the earned interest to the principal:
\[ \text{Total Amount} = P + \text{Interest} = 800 + 480 = 1280 \]
Thus, the student will have a total of $1280 in the account after 4 years.
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