what is the average apr charged on simple-interest loans?

Answer 1

There is NO meaningful answer to this question. Is this a car loan, a fixed rate mortgage, or an unsecured loan? That alone will change the answer by a factor of 2 or more. Your credit score is another MAJOR factor. In short, even if there was an average, NO ONE would ever get a loan at the average rate. And the correct answer today would not be the correct answer tomorrow.