Test statistic upper tail test lower tail test

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

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...
View Full Document

This document was uploaded on 03/05/2014.

Ask a homework question - tutors are online