Expert: Richard J. Raridon - 10/17/2005

Question
I'm working with a scatter graph with trend line.  Formula for trend line is the folloiwng:
y = 58.917x - 18006.
Question: If I run a horizontal line from 10% increments on Y axis to the trend line and drop vertical lines from trend line intersections to X axis, is there a formula to calculate increments between points where vertical lines intersect X axis? As it is I'm printing graph, drawing lines and eyeballing.  

Answer
That's a straight line so there's no problem calculating where the vertical lines intersect the x-axis.  
at x=0, y = -18006 and at x = 305.6, y = 0
The trend line won't be above the x-axis until x is greater than 305.6.  At y=2000 for example, x = 340