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### #22 Repair Costs Vacuum Cleaners You want to buy a vacuum cleaner, .pdf

1. #22 Repair Costs: Vacuum Cleaners You want to buy a vacuum cleaner, and a salesperson tells you the repair costs for Model A and Model B are equal. You research the repair costs of 34 Model A vacuum cleaners and 46 Model B vacuum cleaners. The results of you research are shown below. At a=1.01, can you reject the salesperson's claim? Model A Model B x =\$50 x =\$60 s =\$10 s =\$15 Solution Ans: Test Statistic, t=(x-bar1 - x-bar2)/(s1^2/n1 +s2^2/n2) =(50 - 60)/(10^2/34 + 18^2/46) =-3.16470 Not eq. vars: No Pool (and df calculated with Formula 9-1) Claim µ1 = µ2 Test Statistic, t: -3.1647 Critical t: ±2.644816 P-Value: 0.0023 Degrees of freedom: 73.0571 99% Confidence interval: -18.35722 < µ1-µ2 < -1.642777 Reject the Null Hypothesis Sample provides evidence to reject the claim. From www.TutorTeddy.com
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