Answer:
Step-by-step explanation:
1. Let I = simple interest, r = the rate, t = time (years), P = the initial amount of the loan.
2. I = Prt [the simple interest formula]
3. t = 1.5 years (1 quarter = 3 months so 6 quarters = 18 months or 1.5 years)
4. 161.25 = 4300r(1.5)
5. 0.025 = r (multiply by 100 to make r a percentage)
6. r = 2.5% (Ans)
