Why I get NaN for 24,8 for chi2inv ?

>> c = chi2inv(24,8)

c =

   NaN

In the exercise what we did in school,we used the chi2 table for vx = 24 nad vy = 8 ,and we get w0.95 = 3.155

When I want to search for the chi2nv value , I get NaN out in matlab. How to find this 3,155 wiht matlab?

[the cyclist]

Hi, xy.

Your question is hard to decipher. "vx", "vy", and "w" are not standard parameters of the chi^2 distribution, so it is difficult to guess what you actually calculated in your school course.

Can you explain in words and concepts what you were trying to calculate in your class? Then maybe we can help you translate that into MATLAB. For example, it looks like maybe you are looking for the 95th confidence interval? But we need to know the number of "degrees of freedom" for the chi^2, for example.

[x y]

Hi, We have got basic static on this lecture. Yes we looked for 95th interval, /in chi-squared distribution/

1-alfa ,where alfa is 0,05 ...so w(1-0.95)=w(0.95)

The sample what we work (N is count of info/measurement ) , N1 = 25 , second sample is N2 = 9

Forumla is: Vx = N1 - 1 = 25 - 1 = 24 Vy = N2 - 1 = 9 - 1 = 8

so with this info/number we searched in the chi2 table,and found the number 3,155