AGSC5060 - Statistics for Research Mid-term Fall 2022 6. Surface finishing for corrosion protection is usually the last manufacturing process that takes place in a specialized shop. A new technique for applying bright zinc plating to steel is being tested in a shop in Nashville Tennessee. The variable of interest is the coating thickness, measured in microns (um). The current industry regulated mean thickness is 7.20 um. Ten steel strips coated with new technique were randomly selected and the coating thickness was measured. Sample data are shown below. 7.5 7.8 7.9 7.5 7.8 6.8 7.5 7.4 7.2 8.2 The mean, standard deviation and standard error of these sample data are calculated for you, which are 7.56, 0.39, and 0.12 respectively. Using 5 percent significance level, is there strong evidence that the new technique has increased the mean coating thickness above current industry regulated mean thickness, i.e. 7.20 um? Test the hypothesis at 5 percent significance level. (10 marks) i ) State the hypotheses (1 marks) Ho : H1: ii) Draw and label the sampling distribution for the mean, find critical value and shade rejection region(s). (31/2 marks) iii) As part of hypothesis testing, calculate test statistics, estimate p-value, make decision and draw a meaningful conclusion. (51/2 marks) CONTINUE TO SECTION TWO - MULTIPLE CHOICES