inserting vertical line into a scatter plot

hi,

i have a scatter plot of y-values against some range of x, which say runs from 0 to 1,000. i want to insert a vertical line somewhere along this x-axis to bring attention to that corresponding y-value. what i have been doing is to go to insert --> shapes --> lines, then manually drawing in the vertical line. however, this method is very inaccurate if i want to be very precise in my x-position. what i wish is to incorporate the vertical line into the scatter plot itself.

it is quite straightforward to plot a horizontal line: just give a constant y-value for the whole range of x. however, this method cannot be used for a vertical line, because the 'add trendline' function does not work in this case.

hi, thanks, i see how i can do it now. the 'add trendline' function itself does not show the vertical line; you have to go into format data series --> line colour --> check 'solid line' for the line to appear.