An experiment is designed to determine the effect of four different types of tips in a hardness tester on the observed hardness of a metal alloy. Four specimens of the alloy were obtained, and each tip was tested once on each specimen, producing the following data: Specimen Туре of Tip 1 3 4 9,3 9,4 9,2 9,7 9,4 9,3 9,4 9,6 9,6 9,8 9,5 10 9,9 3 9,7 10,2 10 What is your conclusion about this test at 0.05 level of significance? O a. There is no difference between four specimens of the alloy. O b. At least one specimens of the alloy is different. 685O

Rhino viruses typically cause common colds. In a test of the effectiveness of echinacea, 33 of the 38 subjects treated with echinacea developed rhinovirus infections. In a placebo group, 94 of the 111 subjects developed rhinovirus infections. Use a 0.01 significance level to test the claim that echinacea has an effect on rhinovirus infections. Complete parts (a) through (c) below. a. Test the claim using a hypothesis test. Consider the first sample to be the sample of subjects treated with echinacea and the second sample to be the sample of subjects treated with a placebo. What are the null and alternative hypotheses for the hypothesis test? O A. Ho: P1 #P2 Hy:P1 =P2 O B. Ho: P1 =P2 H1: P1 P2 H1: P1 #P2 Identify the test statistic. (Round to two decimal places as needed.) Identify the P-value. P-value = (Round to three decimal places as needed.) What is the conclusion based on the hypothesis test? the null hypothesis. There sufficient evidence to support the claim that echinacea…

The following is a list of 6 measurements. 11, 17, 7, 8, 16, 20 Send data to calculator Suppose that these 6 measurements are respectively labeled x,, x,, ..., X6: Compute the following. i = 1 ?

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2. Two kinds of bumper guards, six of each kind, were mounted on a certain make of compact car. Each car was then run into a concrete wall at 5 miles per hour and the costs of repairs (in dollars) was recorded. Summary of the data is shown below. n = 6 i = 144 si = 363.20 n =6 i = 149 si = 202.00 Test at the 0.02 level of significance whether it is reasonable to assume that the two populations sampled have equal variances.