Macquarie University Faculty of Science Department of Chemistry and Biomolecular Sciences Analytical Measurement Uncertainty and Method Validation CBMS760 /CBMS860 2013 2010 Tutorial Set 4 /Assignment 4 Hand in complete solutions /working for all three questions below by 6 pm on Wednesday, May 8, 2013. Question 1 In an experimental program to investigate the properties of a thin film plastic coating on ceramic–based resistors, six factors were identified. X1 – Supplier of a basic component of the plastic (there were 2) X2 – Viscosity of the coating at time of application X3 – Thickness of coating X4 – Temperature of the first bake (dry) cycle X5 – Temperature of the second bake (cure) cycle X6 – Speed of the conveyer (a) List the experiments and a random list of run orders for a full factorial design with these six factors using symbolic – and + signs for the levels. Show the complete confounding table. (b) List the experiments and random run orders if we are to run a ½ fractional design . (c) Describe how you would analyse the data in each of the situations defined in (a) and (b) above. Question 2 You are trying to help an ice cream vendor to be able to predict how many ice cream cones he will sell in a given afternoon (so that he knows how much ice cream to buy). He decides, with your help, to run a half fraction of a 25 to study the influence of several factors on sales. The data are given on the next page.
The factors studied and their levels are: Factor Low value (–) High value (+) X1 = temperature /C 24 25 X2 = weather cloudy sunny X3 = number of flavours 5 10 X4 = cone type regular waffle X5 = personality surly happy X1 X2 X3 X4 X5 Number of cones sold – – – – + 105 + – – – – 122 – + – – – 92 + + – – + 149 – – + – – 106 + – + – + 153 – + + – + 111 + + + – – 113 – – – + – 100 + – – + + 146 – + – + + 105 + + – + – 125 – – + + + 105 + – + + – 126 – + + + – 94 + + + + + 156 From the data given, is a prediction equation justified? If so, what is the equation?…