Refer to the information given in P3.4. Nathan now believes his boss should at least consider the possibility of using more than one cost driver to explain the delivery cost; in other words, he would like to explore the viability of a multiple regression model. Required Select the variables from P3.4 that should be considered for further analysis in the multiple regression model. Create a table to specify the key regression output that allows Nathan to evaluate the goodness of fit and significance of slope for each of the selected variables. Run the multiple regression model in Excel with the selected variables from part (a). Evaluate the validity of this multiple regression model using the three validity criteria. Write out the cost formula for this model. Compare the multiple regression model to the individual regression models for each of the selected variables included in this model. Make a conclusion regarding the best overall model to explain delivery costseither the multiple regression model or one of the simple regression models from P3.4. Explain your answer.