Final answer:
The interest rate for the given simple interest formula is found to be 1.5% when the equation 24 = 400 × 0.015 × 4 is solved. To find the rate as a percent, the decimal 0.015 is multiplied by 100%. The original equation reflects the use of a simple interest calculation over a duration of 4 years.
Step-by-step explanation:
The question involves finding the interest rate that is applied over a certain period to calculate the simple interest earned on an account. According to the simple interest formula, we know that Simple Interest = Principal × Rate × Time, where Rate needs to be in decimal form if we're applying it to the formula directly. To find the Rate as a percent, we need to solve the given equation 24 = 400 × 0.015 × 4.
First, we simplify the right side of the equation:
- 400 × 0.015 × 4 = 24
- 400 × 0.015 × 4 = 6 × 4
- 400 × 0.015 = 24/4
- 400 × 0.015 = 6
Then, we solve for the interest rate:
- 0.015 = 6/400
- 0.015 = 0.015 (which confirms our given information)
And finally, to find the interest rate as a percent, we convert the decimal to a percent:
Interest Rate = 0.015 × 100%
Interest Rate = 1.5%
Therefore, the interest rate for the account over 4 years, as a percent, is 1.5%.