Final answer:
The problem involves creating a loan amortization table using Excel with formulas such as IPMT, PPMT, CUMIPMT, CUMPRINC, and RATE, as well as a simple calculation to convert a monthly rate to an APR.
Step-by-step explanation:
This question involves understanding and applying financial formulas in Excel to perform loan amortization, calculate interest and principal payments, and determine annual percentage rates (APR). Specifically, the IPMT and PPMT functions will be used to calculate the interest and principal components of loan payments respectively. The CUMIPMT and CUMPRINC functions will provide cumulative interest and principal paid over a period of time, while the RATE function will help ascertain the monthly interest rate given a change in the monthly payment amount. Finally, converting the monthly rate to an APR requires a simple multiplication formula.
To calculate the ending principal balance, one would typically subtract the principal paid from the previous period's principal balance. As for calculating the APR from a monthly rate, you would multiply the monthly rate by 12 (the number of months in a year) to annualize it.