You may need to change the axis to make it larger to include the points.
Select the X or Y axis with mouse the double click on the highlighted axis.
go to Scale Tab to modify axis as required.

"Bradley Steve" wrote:

My data
781 249.77
781 449.72
766 649.93
761 849.49
723 1049.39
719 1249.65
692 1449.54
672 1649.80
644 1849.70
636 2049.57
597 2249.47
584 2449.72
is used to create a line chart. No problems
I then have been using
=IF(AND(B10F$4,B11=F$4),FORECAST(F$4,A10:A11,B10 :B11)," ")
to calculate a point for a particular value in A.
What I am unable to do is to plot this point on the graph and show lines
from the x & y axes to this point.
Any suggestions?