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# Values of chi squared?

Posted 9 years ago
 While reviewing some problems of statistics that I have already solved, I did the following questions, in a section on contingency tables call chi-square table to know if we reject the null hypothesis or not.Then call tables to obtain the value corresponding to \! \*SubsuperscriptBox[$$\[Chi]$$, $$0.05, 3$$, $$2$$]  which is 7.815, my doubt is can be calculated that value in mathematica? thanks in advance
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Posted 9 years ago
 If you look up "chisquare distribution" in the Wolfram Documentation center you'll find the necessary functions. In[6]:= alpha = 0.05 df = 3 InverseCDF[ChiSquareDistribution[df], 1 - alpha] Out[6]= 0.05 Out[7]= 3 Out[8]= 7.81473 
Posted 1 year ago
 I get the appropriate values: df = 3; alpha = 0.01; InverseCDF[ChiSquareDistribution[df], 1 - alpha] (* 11.34486673014437 *) alpha = 0.05; InverseCDF[ChiSquareDistribution[df], 1 - alpha] (* 7.814727903251181 *) Also, there are many, many ways to mimic the calculator you reference. Here's one way: Manipulate[ InverseCDF[ChiSquareDistribution[df], 1 - \[Alpha]], {{\[Alpha], 3}, {0.001, 0.005, 0.01, 0.05}}, {{df, 1}, 1, 120, 1, Appearance -> "Labeled"}] 
Posted 9 years ago
 Thank you Jim for your help to solve my question, is exactly what I needed,
Posted 1 year ago
 Does this work with any significance level or just 0.05? Got the same results when changed alpha to 0.01, probably doing something wrong. I am also trying to replicate this calculator in Mathematica, but keep getting an error with degree of freedom calculation.
Posted 1 year ago
 Jim thank you very much. I actually refreshed and after changing the code it worked. Also appreciate the Mathematica code that works too!