Alright, I'm trying to figure out how to calculate a critical value using t-distribution in Microsoft Excel... ex. a one-tailed area of 0.05 with 39 degrees of freedom: t=1.685
I know the answer, but how do I get this? I've tried TDIST() TINV() and TTEST() but they all give me different answers. This web calculator: http://www.danielsoper.com/statcalc/calc10.aspx always gives me what I'm looking for but I cannot manage to get Excel to do the same.
Any help would be greatly appreciated!