<P> We will carry out tests of the null hypothesis that the means of the populations from which the two samples were taken are equal . </P> <P> The difference between the two sample means, each denoted by X _̄ i (\ displaystyle (\ overline (X)) _ (i)), which appears in the numerator for all the two - sample testing approaches discussed above, is </P> <Dl> <Dd> X _̄ 1 − X _̄ 2 = 0.095 . (\ displaystyle (\ overline (X)) _ (1) - (\ overline (X)) _ (2) = 0.095 .) </Dd> </Dl> <Dd> X _̄ 1 − X _̄ 2 = 0.095 . (\ displaystyle (\ overline (X)) _ (1) - (\ overline (X)) _ (2) = 0.095 .) </Dd>

Tests in which samples are not independent are referred to as matched pairs or paired samples