Question

XYZ Consumer Protection Authority (XYZ-CPA) is responsible for enforcing laws concerning weights of advertised essential items. XYZ-CPA routinely inspects packages to determine if the net weight of the contents of 20kg rice bags is at least as large as the net 20kg weight advertised on the bag. A random sample of 96 bags were inspected where the net weight content of each of those bags was measured. The mean net weight content calculated from the sample is found to be 20.30kg with a standard deviation 1.20kg. Assuming that the net weight of 20kg rice bags is normally distributed, estimate with 95% confidence the actual mean net weight content of 20kg rice bags. a) You were recently hired as a junior data analyst working for XYZ-CPA. Specify the appropriate formula you would use to solve the problem. Provide a brief reason why you chose the formula. b) Obtain the 95% confidence interval estimate of the actual mean net weight content of 20kg rice bags. Display working. c) Provide an interpretation of the answers you obtained in part b) in the context of the problem. d) Present brief statements of two or three sentences to XYZ-CPA with regard to the outcome of the weight inspection or the quality control

process that you just conducted. Should the XYZ-CPA be satisfied with the outcome? Yes or no? Why? e) Assuming all of the other variables to do the calculation of confidence interval held constant, what would happen to the width of the interval when a higher sample size is used?

Answer 1