I have been monitoring my blood pressure daily with several readings per
day.

I have charted this on a scatter chart and would like to put a connecting
line between the max and min values for one reading.

I.e., Max is 140 and min is 80. I would have two dots representing those
readings but I would like to have a straight vertical line between the two.

My chart should end up looking like,
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If you get the picture. I'm not too good about putting pictures into
words (:

TIA,
Marc