Question

. Two companies manufacture a rubber material intended for use in an automotive application. The part will be subjected to abrasive wear in the field application, so we decide to compare the material produced by each company in a test. A number of samples of material from are tested in an abrasion test, and the amount of wear after 1000 cycles is observed. For company 1, (n = 25) the sample mean and standard deviation of wear are 130 and s 3 milligrams/1000 cycles, while for company 2 (n- 20) these are2 32 and s2 3.5 milligrams/ 1000 cycles. (a) 5 Do the data support the claim that the two companies produce material with different mean wear? Find the P-value and report all relevant steps of the testing procedure Assume that each population is normally distributed with equal variances. Give a 95% confidence interval for the difference in means (b)

Answer 1

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