7.8 Suppose z (x,y) denotes the scores of psychotics, and of normals, respectively, on a verbal...

7.8 Suppose zα ≡ (xα,yα)’ denotes the scores of psychotics, and of normals, respectively, on a verbal achievement test, α = 1,...,11. Suppose also that L(zα) = N(θ, ). On the basis of the observed data it is found that Test the hypothesis that scores of psychotics and those of normals are independent (at the 1 percent level).