Answer :
Using proportions, it is found that the APR was of 6.3%.
What is a proportion?
A proportion is a fraction of a total amount, and the measures are related using a rule of three.
In this problem, 4.7% was paid in interest in 9 months. The APR is the amount that would be paid in a year, that is, 12 months.
Hence, the rule of three is:
9 months - 4.7%
12 months - x%
Applying cross multiplication:
[tex]9x = 12(4.7)[/tex]
[tex]x = \frac{12 \times 4.7}{9}[/tex]
[tex]x = 6.3[/tex]
The APR was of 6.3%.
More can be learned about proportions at https://brainly.com/question/24372153