Question

 

In order to compare the means of two populations, independent random samples of 253 observations are selected from each population, with the following results:

Sample 1	Sample 2
x¯1=1	x¯2=2
s1=190	s2=145

(a)    Use a 97 % confidence interval to estimate the difference between the population means (μ1−μ2).

≤(μ1−μ2)≤
(b)    Test the null hypothesis: H0:(μ1−μ2)=0 versus the alternative hypothesis: Ha:(μ1−μ2)≠0. Using α=0.03, give the following:

   the test statistic z=

The final conclusion is

A. There is not sufficient evidence to reject the null hypothesis that (μ1−μ2)=0.
B. We can reject the null hypothesis that (μ1−μ2)=0 and conclude that (μ1−μ2)≠0.

(c)    Test the null hypothesis: H0:(μ1−μ2)=21 versus the alternative hypothesis: Ha:(μ1−μ2)≠21. Using α=0.03, give the following:

   the test statistic z=

The final conclusion is

A. There is not sufficient evidence to reject the null hypothesis that (μ1−μ2)=21.
B. We can reject the null hypothesis that (μ1−μ2)=21 and conclude that (μ1−μ2)≠21.

Answer 1