Consider that the supply function and the demand function for a product are linear and are determined by the table that follows.

Supply Price	Function Quantity	Demand Price	Function Quantity
200	400	400	400
400	800	200	800
600	1200	0	1200

Let us create the supply and demand function and find the price that gives the market equilibrium.

First we create the supply function.

For this, enter the data of supply price and function quantity from the above table in the lists of a graphing utility.

The figure below shows a partial list of the data points.

The supply function, found using linear regression with a graphing calculator.

The linear equation with supply price p as a function of the quantity supplied q is Thus, the supply function is.