Formulas

Chapter 1: Mathematics of Merchandising

Profit  = Sales – Costs

$\text{Gross Profit} = Sales - \text{Cost of Goods Sold} = Sales - COGS$

$\text{Net Profit} = Sales - \text{Total Costs} = GP - \text{Operating Expenses}$

$\text{Percent Markup} = \frac{Profit}{Cost}$

$\text{Percent Margin} = \frac{Profit}{Sales}$

$Sales = Cost \times (1+ \% Markup)$

$Net = List(1-d_1)(1-d_2)(1-d_3)$

Chapter 2: Functions

$Slope = \frac{Rise}{Run} = \frac{y_2-y_1}{x_2-x_1}$

$\text{Equation of a line: }Y = Intercept + slope \times X$

$Revenue = price \times Quantity = price\times X$

$Costs = \text{Fixed Costs}-\text{Variable Costs}\times Quantity = FC+VC X$

$Profit = Revenue - Costs = price\times X - FC - VC X = (price- VC)X-FC$

$\text{Contribution Margin} = price - VC = \text{markup in dollars for 1 item}$

Chapter 3: Simple Interest

$I = Prt$

$FV = P + I = P(1+rt)$

$P = \frac{FV}{1+rt}$

Chapter 4: Compound Interest

$FV = PV(1+i)^n$

$i = \frac{j_m}{m}$

$PV = \frac{FV}{(1+i)^n}= FV(1+i)^(-n)$

Chapter 5: Annuities

Ordinary Perpetuities:

$PMT = PV\times i$

$PV = \frac{PMT}{i}$

Perpetuities Due

$PMT_{Due} = \frac{PV\times i}{1+i}$

$PV_{Due} = \frac{PMT}{i}+PMT$

To switch to payments at the beginning of the interval:

• Press 2ND BGN (above the PMT key). The display should show END.
• Press 2ND SET (above the ENTER key). The display should show BGN.
• Press CE/C (bottom left corner) or 2ND QUIT (top left corner).

To go back to payments at the END of the interval:

• Press 2ND BGN (above the PMT key) The display should show BGN.
• Press 2ND SET (above the ENTER key). The display should show END.
• Press CE/C (bottom left corner) or 2ND QUIT  (top left corner)

Chapter 6: Investment Decisions