(a) Fit a linear regression model to predict Sales using Price, Urban, US, and write out the fitted model in equation form. Note that some of the variables are categorical. (b) Present the summary of the linear regression fit, and provide an interpre- tation of each coefficient in the model. (c) Is there any evidence of outliers or high leverage observations for this model? Policy: You must do the homework on your own. Please ask the Instructor or the GSIs if you have any