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Choose the one alternative that best completes the statement or answers the ques

ID: 3267205 • Letter: C

Question

Choose the one alternative that best completes the statement or answers the question. Suppose you want to test the claim that mu_1 = mu_2. Two samples are random, independent, and come from populations that are normally distributed. The sample statistics are given below. Assume that sigma^2_1 = sigma^2_2. At a level of significance of alpha = 0.05, when should you reject H_0? n_1 = 14 n_2 = 12 x^bar 1 = 21 x^bar 2 = 22 s_1 = 2.5 s_2 = 2.8 A) Reject H_0 if the standardized test statistic is less than -1.318 or greater than 1.318. B) Reject H_0 if the standardized test statistic is less than -2.492 or greater than 2.492 C) Reject H_0 if the standardized test statistic is less than -2 064 or greater than 2 064 D) Reject H_0 if the standardized test statistic is less than -1.711 or greater than 1.711

Explanation / Answer

given n1 =14

n2 =12

x1 =21

x2= 22

s1=2.5

s2 =2.8

s(x1 - x2) = [(s1²/n1) + (s2²/n2)]

= [(2.5²/14) + (2.8²/12)]

=1.4764

. . x1 - x2
t = ------------------

. . . . s(x1 - x2)
t = (21-22) / 1.4764 = -1.318

so answer is option a