10.1 Mean sd Known

# 484 h0 dparace 0 ha dparace 0 reject h0 if zstat z05

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Unformatted text preview: 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. 2 2 1 2 1 2 2 2 Par Ace Par Ace test statistic upper tail test Hypothesis Tests lower tail test twotailed test Difference Between 2 Population Means (x1 − x2)− D0 zSTAT = 2 2 σ 1 + σ2 n1 n2 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 manufacturer of golf equipment and has developed a new golf ball that has been designed to provide “extra distance.” Par would like to demonstrate that their new Par golf balls are superior to the comparable ball ma...
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## This document was uploaded on 03/05/2014.

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