Final answer:
The effective annual rate of interest is 7.97%.
Step-by-step explanation:
To find the effective annual rate of interest, we can use the formula A = P(1+r/n)^(nt), where A is the future amount, P is the principal amount, r is the interest rate, n is the number of times interest is compounded per year, and t is the number of years. In this case, we have:
A = $1505.37
P = $1285.00
n = 4 (compounded quarterly)
t = 3.25 years (3 years and 3 months)
Substituting these values into the formula, we can solve for r:
$1505.37 = $1285.00(1+r/4)^(4*3.25)
Simplifying the equation, we have:
1.169223 = (1+r/4)^13
Taking the 13th root of both sides, we get:
1+r/4 = 1.01992
Solving for r, we subtract 1 from both sides and multiply by 4:
r = 0.0797, or 7.97%