I'm trying to add a new series to a scatter plot in Excel,
but the new series uses a different set of x-values. I
want to plot it along the same axis as the other series,
but Excel plots the first point at (1, #) and the second
point at (2, #), etc., instead of actually reading in the
x-value and putting it at that place on the plot.

How can I change this so that it plots the point at the
correct/actual x,y values?