Hi,
If there is anyone out there who can explain the difference between the p-values in JMP and the value calculated with the "T-test" function in excel, I would be very grateful. I will give the following explanation to elucidate the quandary that I face.
My experiment consisted of the mass of 82 different samples. This sample set consisted of 4 separate groups (labeled 1,3,4,5) with each group consisting of 25 different samples. When I read the "ordered difference report" from the XY graph measurement, I get the following p-values
However, when I do the same test on the raw data in excel (formatted as the table below)
using the "T-test" function in excel with the following format "=TTEST(A2:A9,A10:A25,2,2)" (choosing a test between group #1 and group #3) the value I get is much different than the one I get in JMP (0.2549). Can anybody give a reason what the difference might be?
Thanks,
Tei