A.n1+n2, B.n11n2,-1 C.n1+n2,+1 D.n1+n2,-2 E.n1+n2,+2
A.已知A藥與B藥均有效 B.不知A藥好還是B藥好 C.已知A藥不會優(yōu)于B藥 D.不知A藥與B藥是否均有效 E.已知A藥與B藥均有效
A.兩樣本均數(shù)差別越大 B.兩總體均數(shù)差別越大 C.越有理由認(rèn)為兩總體均數(shù)不同 D.越有理由認(rèn)為兩樣本均數(shù)差值大于0 E.越有理由認(rèn)為兩樣本均數(shù)有差異