The true annual interest rate to the nearest tenth is <u>16.7%</u>.
<h3>How is interest determined?</h3>
The interest amount for this scenario can be determined by computing the total mortgage payment and subtracting the mortgage amount from the earlier figure.
Since payment was made for 20 months, the interest rate can be annualized using 24 months as below.
<h3>Data and Calculations:</h3>
Price of article = $315.50
Down payment = $31.55
Mortgage amount = $283.95
Monthly payment amount = $16.50
Duration of payments = 20 months
Total payment (mortgage and interest) = $330 (20 x $16.50)
Interest = $46.05 ($330 - $283.95)
Annualized interest rate = 16.7% ($46.05/$330 x 24/20)
Thus, the true annual interest rate to the nearest tenth is <u>16.7%</u>.
Learn more about compound interests at brainly.com/question/19950566
#SPJ1