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QUESTION 1 A procurement specialist has purchased 35 resistors from vendor 1 and vendor 2. Each resistor's resistance is measured as shown in the table. Assume that the population standard deviation from vendor 1 and vendor 2 are unknown. By taking the significance level, a = 0.05, answer the following questions. Vendor 1 99.8 100.0 90.3 96.5 95.3 95.2 105.7 98.9 102.1 105.7 97.7 99.7 103.1 96.6 103.9 105.0 95.4 109.8 109.1 98.6 99.8 97.6 97.3 98.2 96.7 99.8 105.3 103.7 103.5 110.4 99.5 105.4 98.5 96.5 99.4 Vendor 2 107.8 114.7 109.0 106.2 109.2 106.7 106.7 103.0 105.2 105.6 109.3 100.4 109.0 106.5 109.9 103.5 106.2 102.8 106.2 110.5 108.8 101.3 1 12.2 102.7 109.5 108.4 113.5 104.3 109.8 111.5 106.8 105.4 116.3 108.7 112.3 (a) Calculate the mean and standard deviation for both vendors. (4 marks) ( b ) Perform an appropriate statistical hypothesis testing to determine whether the procurement specialist can claim that the mean of resistance from vendor 1 is significantly different from the mean resistance of vendor 2. (6 marks) (c) If you were the procurement specialist and you were about to select only one vendor in the future, which vendor will you choose to purchase the resistors? Give your justifications with appropriate statistical test. (6 marks) (d) Construct a 95% confidence interval on the difference in mean resistance for the two vendors. (4 marks)