9.5 Tests Concerning Two MeansHo: Hi = P2 (can also be written as µi - H2 = 0) OR HI < Hz OR HIZ 2Ha: Hi < µ2 OR µi > µ2 OR µi # µ2Determining the Test StatisticCaseTest Statistic1For o1 and o2 known; Independent SamplesX1 – x2z =+n22For ơ1 and o2 unknown AND ni, n2 2 30; Independent SamplesX1 — х2z =Sĩ+n2For ơ1 = 02 unknown (assumed equal) AND ni, n2 < 30; Independent Samplestaken from Normal Populations3(m-1)s +(n2 -1)s?х1 — х2t =where Sp11+nị +n2 - 2Sp.with v = ni + n2 – 2 degrees of freedom S is the pooled sample variance.4For paired observations; RELATED Samples with Paired Differences coming froma Normal Populationdt =SdInwith v = n-1 degrees of freedom Suppose that hemoglobin levels in white males over age 11 are normally distributed withvariance 1.462 and that those for white males age 11 or under are normally distributed withvariance 0.867. Independent random samples of 10 older and 20 younger white males areselected and produce sample means of 13.47 g per 100 ml and 12.64 g per 100 ml,respectively. Do the data indicate that older white males have higher hemoglobin levelsthan younger white males? Use a 0.01 level of significance.

Answered: Suppose that hemoglobin levels in white…

MATLAB: An Introduction with Applications

6th Edition

ISBN:9781119256830

Author:Amos Gilat

Publisher:Amos Gilat

Chapter1: Starting With Matlab

Section: Chapter Questions

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A researcher is studying how much electricity (in kilowatt hours) people from two different cities use in their homes. Random samples of 13 days from Nashville (Group 1) and 14 days from Cincinnati (Group 2) are shown below. Test the claim that the mean number of kilowatt hours in Nashville is less than the mean number of kilowatt hours in Cincinnati. Use a significance level of a = 0.10. Assume the populations are approximately normally distributed with unequal variances. Round answers to 4 decimal places. Nashville Cincinnati 902.6 892.9 904.9 897.5 905.2 904.1 911.4 883.9 898.7 887.7 889.7 907.2 899.1 Ho: M₁ What are the correct hypotheses? Note this may view better in full screen mode. Select the correct symbols for each of the 6 spaces. 921.2 931.1 908.3 939.6 898 934.6 906.6 921.2 907.5 902.4 883.6 893.1 Test Statistic = 941.4 923.6 p-value = H₁: M₁ Based on the hypotheses, find the following: H₁₂ H₂ Or
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The variability in the amounts of impurities present in a batch of chemical used for a particular process depends on the length of time the process is in operation. A manufacturer using two production lines, 1 and 2, has made a slight adjustment to line 2, hoping to reduce the variability as well as the average amount of impurities in the chemical. Samples of 25 and 25 measurements from the two batches yield 1.04, respectively 0.51 variances. Do the data present sufficient evidence to indicate that the process variability is less for line 2? Use 5% significance level. Conduct a hypothesis test of the airline executive’s belief. [α = 0.05]
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