Howdy, Jerry. You can set this up systematically, following Pierre's lead.
Say your data is in E10:Q15, then leave that data alone, and in E20:Q25, put the formula in E20:
=E10*Scale
and copy to the entire range, E20:Q25. Where Scale is a named range (cell) (say in cell B2).
Then build your graph based on E20:Q25.
With this set up, you only need change the value in that cell for all formulas to automatically adjust. And for further refinement, set up a lookup table on the Control worksheet, and you can have the Scale cell a formula based on the MAX value of the data in E10:Q15. That way you can have it adjust according to each worksheet that you have to do, and you don't even have to change he value in the Scale, since it is a formula that automatically changes.