The Free-Hand Method

About free-hand wage lines

Drawing a job rate line free-hand is a simple method that works best when the points marking the job value and job rate of each job class form a straight line.

The job rate line should be drawn to fit the points on your scattergram as closely as possible. It is not necessary that any of the points actually be on the line as long as the line you draw best represents the pattern of points.

Calculating an average point

It is easier and more accurate to draw a straight line free-hand if you first calculate an average point. The average point is determined by taking the average of the job values and the average of the job rates for all male job classes in the representative group. The average job value and the average job rate - which become the average point - are then plotted on the graph. This average point becomes the pivot point through which any male job rate line would run.

These are the representative male job classes and the pivot point calculation:

Chart # 10

The male job rate line will run through the point on the graph where a job value of 520 * points (rounded from 519.66) and a job rate of $23.67 * intersect.

Plotting a wage line free-hand

Before using their computer's regression program, STC quickly plotted a male wage line using graph paper, a pencil and a clear ruler. As shown on the graph below, they:

Chart # 11
PV Male Wage Line

Double-checking free-hand results using regression analysis

The above graph shows a single female job class paid below the PV male wage line and in need of an adjustment.

The Committee double-checked these results using Regression Analysis. More information on regression can be found on the next page.