Position g Normalize Y (ctrl-shift-N)

Multiplies the Y values of a given plot in such a way that the largest value of the whole plot becomes equal to a value you specify.

 

When you draw a selection rectangle before doing Normalize Y, only the Y values of the data points within the X range of the rectangle will be used to calculate the multiply factor, after which the whole plot will be multiplied with this factor. 

 

The calculated multiplication factor will be stored in the Multiply Y default value, so that you can later multiply other plots with the same factor as well.