The following estimated regression equation relating sales to inventory investment and advertising expenditures was given. )7 = 27 + 11X1 + 8X2 The data used to develop the model came from a survey of 10 stores; for those data, SST = 18,000 and SSR = 12,780. (a) For the estimated regression equation given, compute R2. R2 = (b) Compute R52. (Round your answer to two decimal places.) 2 _ Ra (c) Does the model appear to explain a large amount of variability in the data? Explain. (For purposes of this exercise, consider an amount large if it is at least 55%. Round your answer to the nearest integer.) The adjusted coefficient of determination shows that % of the variability has been explained by the two independent variables; thus, we conclude that the model --Select--- a explain a large amount of variability