Assuming the interest is compounded monthly, the interest rate, to the nearest tenth of a percent, that would be required for Sophia to end up with $1,170 is 3.0%.
What is the interest rate?
To get the solution to the problem, we would use the formula for compounding interest as follows:
A = P(1 + r/n)ⁿˣ
Where A = $1170, p = $820, n = 12, r = ? t = 12
$1170 = 820( 1 + r/12)¹² ˣ ¹²
1170/820 = (12 + r/12)¹⁴⁴
144√1170/820 = (12 + r/12)
12 + r = 12 * 144√1170/820
r = 0.296
≈ 3.0%