I have a scatter-point chart and I have been able to plot the linear
trendline through those scatter points. I then formatted the linear
trendline and got the equation for the line.

However, I noticed that the y-intercept (7.9...) of the actual line that was
graphed by Excel is not the same as the y-intercept (8.9573) for the equation
that Excel derived from the graphed line. The actual Excel graphed line and
the line the equation appear to be parallel to each other. As a result,
entering data into the equation supposedly derived from the graphed line will
not result in the line that was graphed by Excel.

Thank you in advance for your help