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Q1. In studying the decay of an aerosol spray, experimenters obtained experiment results shown below, where x is the age in minutes of the aerosol and y is its observed dispersion at that time. Physical considerations suggested a proportional relationship y = Ox. The objective is to fit the data to this linear model. X V y (replicate) 9 6.16 6.06 21 9.88 8.22 34 14.35 16.50 41 21.56 19.21 a) Use the weighted least squares method to estimate the parameter o . b) Calculate 95% confidence interval for the parameter. c) Predict mean response of y for x = 50 and determine its 95% confidence interval