Stat 312 Homework Problems - Week 10

H0 c s 0 versus ha c s 0 the test statistic is the

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Unformatted text preview: he following test. H0: C - S = 0 versus Ha: C - S > 0 The test statistic is The individual standard errors are n 15 15 mean 540 554 s 21 15 and , so = 25 degrees of freedom will be used. The p- The degrees of freedom are value is P(t25 > 2.10) = .023. Since there was no significance level given, the common default is to use = .05. In that case, our p-value is less than .05, so we reject the null hypothesis. The data support the beli ef that the cola cans have greater mean compressive strength than the strawberry drink cans. 30. The data is summarized in the table. a. The estimated standard error is individual standard errors are The and Type Fiberglass Carbon n 26 26 mean 33.4 42.8 s 2.2 4.3 . The degrees of freedom are given by . So the degrees of freedom are = 37. A 99% confidence interval for - will use the critical value t.005;37 = 2.716, and is given by (42.8 – 33.4) 2.716(.947) = 9.4 2.57 = (6.83, 11.97). Since this interval does not include zero, we are 99% confident that the carbon beams are stronger than the fiberglass beams. b. No. A 99% confidence upper bound for will use the critical value t.01;37 = 2.432, and is given by...
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This note was uploaded on 09/17/2012 for the course STAT 312 taught by Professor Chung during the Spring '04 term at Wisconsin.

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