How to extrapolate Weibull Plot Reference Line Data

I am trying to extrapolate data by using the reference line data however for some reason the YData for line is not making any sense to me because it does not correspond to the y-axis. Below is a picture of what I am seeing witht the corresponding data.

My initial approach was to use the XData and YData to make a y=mx+b plot however, the YData is not adding up therefore I am getting the wrong answer.

Any recommendations on how I should go about finding the equation of the reference line would be grateful.