5. Tough Gear wishes to estimate the difference in mean number of days a hammer takes to sell. They are comparing a wooden handle hammer and a fiberglass handle hammer. A 90% confidence level is to be used to compare results. For wooden handle the population standard deviation is 3.4. the sample size, 1, = 50, and the sample mean is 20.6 days. For the fiberglass handle the population standard deviation is 4.0, the sample size. 1, -80, and the sample mean is 15.5 days. Pets Inc, is comparing the results of two different samples of dog collars baches on independent assembly lines. The sample standard deviations are for Assembly line 1 and for Assembly line 2. A 90% confidence level is to be used to compare the results. Assume the population variances for both lines are the same. We have the following data from the samples: Assembly Time Asembly Time -195 5-10 -210 7. Tough Gear, is considering two alternative types of machines for purchase. Tough Gear wants to know if there's any significant difference in production speed. A trial is done with both machines and they are tested for two weeks. After two weeks they found the following information: Machine 1: 0-40, sample means -134 minutes, standard deviations were o = 20 min Machine 2: n=50 sample mean =119 minutes standard deviations on = 30 min. What conclusion should be reached if they want 0.05? Use critical value approach. b. Use the p-value approach & Fashion Fab believes that their current purchasing plan provides a much better results than a new plan which the manufacturer is proposing. They wish to use an a -0.05 level for the comparison. To convince Fashion Fab to consider the new purchasing plan the manufacturer has randomly selected 3 months of results for the current plan and 4 months of results for the new plan. Compare the mean results for each using a=0.01 level. The following sample data were observed Current plan New plan 26 178 166 -14 What conclusion should we make? Use critical value approach. Assume the population variances are the same for both plans