Use Excel to create a scatter plot for each possible cost driver in comparison to delivery cost, shown weekly. Make note of any linearity concerns for any of the variables. Run a regression model for each possible independent variable, evaluating each variable using the three validity criteria. Write out the cost function for each model. Based on your analysis of each of the three possible cost drivers, recommend which cost driver(s) should be considered in explaining/predicting weekly delivery costs going forward. If Nathan's boss prefers to model these weekly delivery costs with just one independent variable, which variable will she choose? Specify the final model if that variable is selected