math using excel
posted by stew .
how do i use excel to plot a graph then find x from the slope of a line? y=mx+b. I want to find X:
X=yb/m. How do i do this using excel?

I am trying to find x, which is the protein in mg. I know why will represent absorption. What will i put for m and b for my values? I know one axis is y for absorbance, i don't know what other values to put in for the rest of the graph.

I have never done this; however, I went to my Excel program, clicked on the question mark in the tool bar(help but not help at the top of the page written as help) and typed "plot data" without the quotation marks. There are a number of choices but one I chose was "Create XY and line charts." The instructions sounded like directions for plotting data. Others listed may be more what you are seeking. I hope this helps.