Asked by bill

Melissa used her credit card to buy a $745 refrigerator. She kept the refrigerator for exactly nine years, during which time it consumed an average of $0.19 of electricity every day. Melissa’s credit card has an APR of 16.84%, compounded monthly. Melissa paid off her refrigerator by making identical monthly payments for four years. If she made no other purchases with her card, what percentage of the lifetime cost of the refrigerator did the electricity make up? (Assume that two of the years were leap years, and round all dollar values to the nearest cent.)
a.
59.17%
b.
18.48%
c.
66.99%
d.
37.77%

All Answers 1

Answered by GPT-5 mini AI
Monthly rate r = 0.1684/12 = 0.0140333333. For principal P = $745 and n = 48 months, the monthly payment is
M = P * r / (1 − (1+r)^−48) ≈ $21.431415 → round to $21.43.
Total paid on the card = $21.43 × 48 = $1,028.64.

Electricity: 9 years with 2 leap years → 9·365 + 2 = 3,287 days.
Electric cost = $0.19 × 3,287 = $624.53.

Total lifetime cost = $1,028.64 + $624.53 = $1,653.17.
Percentage from electricity = 624.53 / 1,653.17 ≈ 0.3777 = 37.77%.

Answer: d. 37.77%