To find the interest rate on the savings account, we can use the formula for simple interest:
Interest = Principal × Rate × Time
In this case, the principal (P) is $3,150, the interest (I) is $286.65, and the time (T) is 7 years. We need to solve for the rate (R).
286.65 = 3,150 × R × 7
To find R, we can rearrange the equation:
R = 286.65 / (3,150 × 7)
R ≈ 0.013 or 1.3% (rounded to the nearest tenth of a percent)
Therefore, the interest rate on the savings account is approximately 1.3% or 0.013 in decimal form.