Hi all I am wanting to do a t-test in Excel (for a class I am teaching). So as a practice, I did this (in columns A and B): 34 13 35 23 23 29 13 200000 14 200000 56 12 43 These are my two groups, with means: 31.14285714 66679.5 Certainly the means seem different! However, the ttest procedure gave me this p-value: 0.174751284 The formula was this: =TTEST(A1:A7,B1:B6,2,3) What on earth is going on? Can anyone explain? Can anyone suggest the correct approach? P.