Chi Squared Distribution with Over 100 Degrees of Freedom
Date: 03/21/2005 at 07:23:13 From: Simon Subject: chi squared distribution I want to find the critical value for the chi squared distribution with 198 degrees of freedom. I can only find tables on the internet up to 100 degrees of freedom. Can you help?
Date: 03/21/2005 at 10:17:18 From: Doctor George Subject: Re: chi squared distribution Hi Simon, Thanks for writing to Doctor Math. The chi squared distribution is asymptotically normal as the number of degrees of freedom (n) becomes infinite. Since the chi squared distribution has mean = n and variance = 2n, you can get a very good approximation using the normal distribution with this mean and variance. If you try this experiment with 100 degrees of freedom you will see that the approximation is very good. That is why tables are usually not made for more degrees of freedom. If you do not think the approximation is good enough you will probably need to write or buy software to do the calculations. Does that make sense? Write again if you need more help. - Doctor George, The Math Forum http://mathforum.org/dr.math/
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