10.1 Mean sd Known

# Test statistic upper tail test lower tail test

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Unformatted text preview: de by their competitor, Ace, Inc. In a test of driving distance using a mechanical driving device, a sample of Par golf balls was compared with a sample of Ace golf balls. In a sample of 120 balls, the Par balls averaged 275 yards and in a sample of 80 balls, the Ace balls averaged 258 yards. Based on data from previous driving distance tests, the two population standard deviations are known with σPar = 15 yards and σAce = 20 yards. test statistic upper tail test lower tail test twotailed test Difference Between 2 Population Means ( x Par - x Ace ) - D0 z STAT = s Par 2 s Ace 2 n Par + n Ace = 6.484 H0: DPar–Ace ≤ 0 Ha: DPar–Ace > 0 reject H0 if zSTAT > z.05 or pvalue<0.05 H0: μ1 – μ2 ≥ D0 Ha: μ1 – μ2 < D0 reject H0 if zSTAT < zα or p-value<α H0: μ1 – μ2 = D0 Ha: μ1 – μ2 ≠ D0 reject H0 if zSTAT < –zα/2 or zSTAT > zα/2 or if p-value<α Example Can we conclude with 95% confidence that the mean driving distance of Par balls is greater than Ace balls? Hypothesis Tests Par, Inc. is a manufact...
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## This document was uploaded on 03/05/2014.

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