Doubts on chi square dist


1)isnt it mean of chi sq dist with degree of freedom k is equal to k? so the answer should be 160? may be?
2) as the degree of freedom increases the curve becomes bell shaped? not flat?

The result you probably are referring to is mean of \chi^2 with k degree of freedom (i.e. \chi^{2}(k)) = k

160 is the mean of height (not mean of \chi^2(k)) of 150 men. Probably revisiting the lecture videos again might help.

You are right. Actually for n=1, its steep and skewed as n increases, it moves towards bell shaped (‘normal’), with decreasing height (area spreads out), Flatness refers to this decreasing height.

Hi, Adding to Point 2 made by Aditya,
As degrees of freedom increases, yes it does approach to bell shaped curve, but the bell also gets flatter. Which is what the answer in that question wanted to touch up. :slight_smile:
Hope this helps!

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