Loan Payment Formula
Symbolic Formula in Excel Format	Interpretation
PMT = P*(r/n)/(1 - (1 + r/n)^(-n*t))	The amount PMT that must be paid n times per year for t years to pay off a loan principal amount of P at an APR of r is given by the right-hand side of the formula.
Sample problem: What is the monthly payment amount needed to pay off a loan principal amount of $10,000 over 4 years, given an interest rate of 7.3%?
Inputs:					Formatting instructions:
P	r	n	t		Dollar amounts: format as Currency with 2 decimal places
$10,000.00	0.07%	12	4		Rate: format as Percentage with 1 decimal place
Application of the formula to the inputs:				Periods/Years: format at Number with 0 decimal places
Inflation Rate Formula
Symbolic Formula in Excel Format	Interpretation
IR = (new CPI - old CPI)/(old CPI)	Given an old CPI value at one point and a new CPI value n years later, the n-year inflation rate IR is given by the right-hand side of the formula.
Sample problem: The CPI value in January 2009 was 211.143; the CPI value in January 2014 was 233.916. What was the 5-year inflation rate between January 2009 and January 2014?
Inputs:					Formatting instructions:
CPI New	CPI Old	IR	n =		CPI values: format as Number with 3 decimal places
233.916	211.143	0.108	5		Inflation rate: format as Percentage with 3 decimal places
Application of the formula to the inputs: