Why do you want to do this by hand? There isn't really a nice closed form expression for the CDF or the inverse (unless you have some special functions already programmed). Why do you want to do this by hand?
Hi All,
I am trying to use calculate for two-tailed inverse of the student`s t-distribution function presented by Excel functions like =TINV(probability, deg_freedom)
For instance: The Excel function below;
N= 1223
Alpha= 0.05 (for 95%)
Then;
= TINV(0.05/1223,1223-2)
= TINV(0000408831, 1221)
= 4.0891672
I already got the equation for above excel function but does not work for probability (alpha/N) and just work probability alpha 0.05. I can calculate inverse Student-t value using approximations values for X, Y and Z. The equation below:
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Tinv = exp(X + Y / df + Z / df2)
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Another calculator by webpage on http://www.danielsoper.com/statcalc3/calc.aspx?id=10 but I don`t know this equation.
The point is how to calculate that value by hand for TINV like excel or webpage?
Thanks in advance.
Cheers! Andre
Why do you want to do this by hand? There isn't really a nice closed form expression for the CDF or the inverse (unless you have some special functions already programmed). Why do you want to do this by hand?
I don't have emotions and sometimes that makes me very sad.
Hi Dason,
I would like to use for my thesis in geological research. I want know how to calculate by hand step by step. Do you have softcopy textbook?
I hope that someone can solve my problems.
Appreciate your helps.
Cheers!
it's not really something you can do by hand. There are approximations but there is no closed form solution. It's not really an enlightening endeavor either - is there a reason you can't just use software?
I don't have emotions and sometimes that makes me very sad.
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