nsider a hypothesis test of difference of means for two independent populations x1 and x2. (a) What does the null hypothesis say about the relationship between the two population means? O Ho says that the population means are equal. O Ho says that the population standard deviations are equal. O Ho says that the population standard deviations are different. O Ho says that the population means are different. (b) If the sample test statistic has a z distribution, give the formula for z. H1 - H2 O = 2 n2 O = + n2 Hy - H2 O = V n2 O = V1 + 522 n1 n2 Hy – Hz - (x, - x2) O = s,2 522 n2

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