# T values and Z values

Could someone be kind enough to post t and z critical values (both 1 & 2 tailed) for 90%, 95% and 99% confidence level? Thanks in advance. Cheers

T-values depend on degrees of freedom so nobody memorizes those (well…almost nobody) For C.I. and two sided tests know - 90% Z = 1.645 (alpha = 0.1) 95% Z = 1.96 (alpha = 0.05) 99% Z = 2.58 (alpha = 0.01) For one sided tests know alpha = 0.1 => Z = 1.28 alpha = 0.05 => Z = 1.645 alpha = 0.01 => Z = 2.33 That’s all…

Tks Joey. BTW, for t-values, degree of freedom is n-1. Am i right?

n-1 regularly, for hypothesis’ testing r^2 the formula sez n-2

maparam Wrote: ------------------------------------------------------- > Tks Joey. > BTW, for t-values, degree of freedom is n-1. Am i > right? On the next couple of levels you’ll be cursing degrees of freedom becaus ethey depnd on the hypothesis test. On LI it’s n-1 for tests about means and n-2 for tests about association between variables like regression and correlation. On LII it’s lots of different things.