I think I understand... I'll try to explain this.
To make a chart you need your two constant values, which go along the X axis (across the bottom) and Y axis (on left side going top to bottom). In your case you have fuel lbs/hr as your Y axis and your RPM's as your X. The other thing you need, is your changing data (what you called variable data).
Open a new Excel workbook and in cell A2, A3, A4, A5, A6 enter your fixed values for fuel lbs/hr which will end up on the Y axis; such as:
20 lbs/hr
40 lbs/hr
60 lbs/hr
80 lbs/hr
100 lbs/hr
Then in cell B1, C1, D1, E1, F1 enter your fixed values for RPM's which will end up on the X axis; such as:
100 200 300 400 500
You can put little gridlines in this "area" that you just created and shade it in blue or something, to easily see it when you fill in your variable data. It should be a 5x5 grid (5 columns by 5 rows)
Anywhere in that grid:
- hit the chart icon
- select Line Graph
- hit Next
- hit that little square icon at the end of the "white bar" that Data range:
- highlight from cell A1 to F6
- hit the little icon again, at the end of the "white bar"
- hit Next
- Under the "Title" tab, you can put whatever title you want, under Chart Title
- Under X axis you can put RPM's
- Under Y axis you can put whatever this chart is supposed to be measuring
- On the Legend tab, you can click the "Bottom" button.
- Under the Data Labels tab, you can put Value
- hit next then hit Finish
This puts the chart into the same sheet as your data. If you would rather have a separate sheet for your chart, repeat the steps above, but on the last step, select "As new sheet", then finish.
As a test, put data across one row. For example, on row 4 (which should be the "60 lbs/hr" row), enter in cell B4 a value of 20. In cell C4 enter 60 D4 enter 50 E4 enter 80 and F4 enter 30. As you change your variable data, you'll see that the chart updates itself.
This is a farirly simple chart example, but hopefuly it's a start bud.
gary