Compare the means of two populations using 96% confidence interval:
In order to compare the means of two populations, independent random samples of 484 observations are selected from each population, with the following results:
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Sample 1
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Sample 2
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xi
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x2
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st = 105
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s2 = 165
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(a) Use a 96 % confidence interval to estimate the difference between the population means (mean 1 - mean 2)
(b) Test the null hypothesis: Ho: (mean 1 - mean 2) = 0 versus the alternative hypothesis: Ha : mean 1 - mean 2) is not equal to 0. Using alpha = 0.04, give the following:
1. the test statistic z=
2. the positive critical z score the negative critical z score: Test the null hypothesis: Ho: (mean 1 - mean 2) = 21 versus the alternative hypothesis: Ha: (mean 1 - mean 2) not equal to 21. Using alpha = 0.04, give the following.
- the test statistic
- the positive critical z score
- the negative critical z score