Please provide all solutions in an excel file using the link below;

Question 1 Using the data provided in "Assignment 3.xlsx (Car prices)", answer the following questions. (a) Which independent variable has the most significance for predicting price? (10) (b) Develop the best possible multiple linear regression model for the data using all the variables. (10) (c) Develop a piecewise linear regression model for the independent variable, mileage and dependent variable, price. Compare the results with the multiple linear regression model. (10) Question 2 Using the data provided in "Assignment 3.xlsx (sales)", answer the following questions. (a) Develop a time series plot. What pattern exists in the data? (10) (b) Develop a moving average model with k = 3. (10) (c) Develop an exponential smoothing model with alpha = 0.2. (10) (d) Develop a linear regression model with time and sales. (do not use quarters, time = 1,2,3,.... 16) (10) (e) Develop a regression model with quarters. Use 3 dummy variables for quarter 1, 2 and 3 respectively. (10) (f) Compare the models built in question 2,3,4 and 5 using MAE, MSE and MAPE. Identify the best model