Sue -
A pivot table will help to make this chart. I'll work through this
example with the following data.
X Y
13 10
15 10
11 10
10 14
14 14
12 11
10 10
11 14
13 12
13 13
14 13
11 11
14 15
15 10
14 11
13 10
12 14
11 11
11 11
10 11
11 14
Select the range with your data, then choose Pivot Table Report from
the Data menu. When you get to the Layout step, put Y in the Rows area,
and X below it in the Rows area. Drag Y into the Data area, and make it
display the Average of Y; again drag Y to the Data area, make this one
display Count of Y. The top part of the pivot table looks like this:
Y X Data Total
10 10 Avg Y 10
Count Y 1
11 Avg Y 10
Count Y 1
13 Avg Y 10
Count Y 2
15 Avg Y 10
Count Y 2
10 Avg Y 10
10 Count Y 6
11 10 Avg Y 11
Count Y 1
Double click the buttons for the Y and X fields, and set the Subtotals
to None. Then drag the button for the Data field above the Total label.
Now the pivot table looks like this:
Data
Y X Avg Y Count Y
10 10 10 1
11 10 1
13 10 2
15 10 2
11 10 11 1
11 11 3
12 11 1
14 11 1
12 13 12 1
13 13 13 1
14 13 1
14 10 14 1
11 14 2
12 14 1
14 14 1
15 14 15 1
You need to generate an XY Scatter chart from the X and Avg Y columns.
If you're using Excel 2000 or later, Excel will try to make a Pivot
Chart. To avoid this aberrant behavior, select a blank chart and start
the chart wizard. On step 1, select a scatter chart. On step 2, click
on the Series tab, click add, type whatever name you want (or click in
the Name box and then select a cell that contains the name), clear the Y
Values box and select the Avg Y data in the pivot table, then click in
the X Values box and select the X values in the pivot table.
Finally use Rob Bovey's Chart Labeler (a free Excel addin from
http://appspro.com) to apply the labels in the Count Y column to the
data points.
- Jon