The Dotplot is similar to the histogram but frequency is represented by the number of dots. A dot represents one observation or a group of observations if they are of the same or about the same value. The Dotplot is useful for comparing distributions.
1. Choose ProcessMA > Graphs > Dotplot.
2. In Variable, select the column containing the data.
3. Click OK.
Optional
4. In Segment by, select a column containing subgroup codes.
Note To select a column of data into a textbox, double-click on any of the column names shown in the list on the left of the dialog box while in the textbox.
Variable: Numeric.
Segment by: Text or Numeric. Must contain equal number of data points as the Variable.
A company makes steel bolts using four different machines. You want to assess if the dimensions of the steel bolts made by different machines are the same. You want to use the Dotplot to compare the distributions.
1. Open worksheet ProcessMA > Tools > Data Files > Stat.xls.
2. Choose ProcessMA > Graphs > Dotplot.
3. In Variable, select N – Dimension.
4. In Segment by, select O – Machine.
5. Click OK.
