Figure 1-13.

E-4 pay history column chart

Figure 1-14.

Plotting on the X-axis

When constructing a vertical bar or column chart, the space between the

columns is 2/3 the width of a column. For this chart, you must mark off

23 equal spaces with 2/3 of the width of a column before the first mark

and an equal space after the last mark. To ensure the correct spacing,

you should use a scale to mark off the 23 equal spaces.

Twenty three equal spaces may seem like an excess number of space for a

9-year period. However, you must consider the 2 to 3 ratio for the width

of the columns and to the spaces; A single column requires three spaces

and a distance between two columns requires two spaces to maintain the 2

to 3 ratio. Therefore, you can determine the number of columns using

simple mathematics.