How to determine significant diff or not btwn slope and intercept of two datasets?

#1
Hi, this is for some research I'm doing in a lab, and I cannot for the life of me figure out how to determine if the two regression lines' slopes and intercepts are significantly different or not (I'm hoping they aren't!). From looking at the graph below, it seems obvious that they should not be significantly different (well maybe intercepts could be), but I need to confirm this in order to assert the interpretation credibly.

In Minitab, I've gone through ANOVA, General Linear Model (ANCOVA), Test for Equal Variances... :shakehead

Can anybody provide some insight into how I can test these things and get results in Minitab or Excel? JMP would work too. My supervisor said to see about getting 95% CIs for each slope or something and compare them, but I cannot figure out how to do that for the line - I could only do it for each variable in both groups. :confused:

An image of the data and regression lines are below:

Axis labels are not relevant.

Thank you so much for any help!!
 
Last edited:
#2
Re: How to determine significant diff or not btwn slope and intercept of two datasets

Bump - I have still been unable to figure this out after hours of messing around