Summary
When ……….. form a random sample from a normal distribution with unknown mean … and unknown variance ….. we can test hypotheses about … by using the fact that …………. has a t distribution with …. degrees of freedom. Let …. denote the quantile function of the …. distribution with … degrees of freedom. Then, to test … versus … at level … for instance, we reject … if … . To test … versus … , reject … The power functions of each of these tests can be written in terms of the d.f. of a noncentral … distribution with … degrees of freedom and noncentrality parameter…