08-16-2011 01:25 PM
I want to determine if the the response to one treatment is different from another. I have multiple animals, some that received drug A and others drug B. They are distrubuted based on starting weight, so the x-axis is a continuous variable. The y-axis is response time in seconds. Essentially I would like to determine whether the slopes of the best fit lines are similiar or different.
08-16-2011 02:09 PM
build a linear model y= intercept+x+trt +x*trt and then test the coefficient for x*trt to see if the slopes are zero. to test if both treatments have the same intercept then test the trt coefficient to see if it zero.