50. Let Xl" ' " XII ; Yl , .. . ,y" be samples from N(~, 11 2) and N( 71 , T 2) respectively. Then the confidence intervals (43) of Chapter 5 for T 2 /11 2 , which can be written as [(}j - yf k[( X; - X)2 T 2 5 2511 k[(}j _ y)2 [(X; - xf ' are uniformly most accurate equivariant with respect to the smallest group G containing the transformations X: = aX +

b, Y;' = aY + c for all a*" 0,

b, c and the transformation X: = dY;, Y;' = X;/ d for all d *" 0. ICr. Problem 7.]