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**Unformatted text preview: **F test to compare two variances ... p-value = 0.3975 alternative hypothesis: true ratio of variance s is not equal to 1 95 percent confidence interv a 0.02967475 3.42920369 sample estimates: ratio of variances 0.4417034 The Welch-Satterthwaite t test is an alternative to the two sample t-test with equal variance, and is used when the assumption that the two populations have equal variances seems unreasonable. The prob-lem with this method is that it is asymptotically a t distribution. >t.test(x,y,alternative="two.sided", conf.level=0.9) Welch Two Sample t-test data:x and y t = -0.7073,df = 4.778 p-value = 0.5124 alternative hypothesis: true difference in means is not equal to 0 90 percent confidence interval:-20.361647 9.861647 Review problems. Compute a CI for X- Y in the previous Example. Example 9.7...

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