Assistance with 1 Homework Question

I need help with “1 question” for my homework. This is in reference to book – “Introduction to Finance: Markets, Investments and Financial. 15th Edition – by Ronald W. Melicher, Edgar A. Norton…I SHALL PROVIDE “CHAPTER 8” ONCE THE TUTOR HAS BEEN SELECTED.

Please note that I need an authentic original answer (at least 1-2 paragraphs – “in your own words”). I will check for plagiarism prior to final acceptance. Thank you

****QUESTION – What is the interest rate, and how is it determined?***