Noel Devine bought a new dishwasher for $320. He paid $20 down and made 10 monthly payments of$34.

What actual yearly interest rate did Noel pay?

Total monthly payments: 10*$34 = $340.

Credit amount: $320 - $20 = $300

Interests : $340 - $300 = $40

interest rate: interest*100 / credit = 40/300*100 = 13.33%

yearly interest rate = (interest rate / number of months) * 12 = 13.33%*12/10=16%