Question

Define – variate for n d.f.and mention its mean, variance.

Answer 1

Let Z1, Z2, Z3,…Zn be n independent SNV’* ,

Then,χ2 = Z12 ,+ Z22 + Z32 , …. + Zn2 is a χ2 – variate with n d.f; Mean

= n, Var (x) = 2n.