The accompanying data file contains 20 observations on the response variable \\( y \\) along with the predictor variables \\( x_{1} \\) and \\( x_{2} \\). Click here for the Excel Data File a. Estimate a regression model with the predictor variables \\( x_{1} \\) and \\( x_{2} \\), and then extend it to also include the interaction variable \\( x_{1} x_{2} \\). What is the estimated regression coefficient for the predictor variable \\( x_{1} \\) and \\( x_{2} \\) in both models? Note: Negative values should be indicated by a minus sign. Round your answers to 2 decimal places. b-1. Which is the preferred model for making predictions? The accompanying data file contains 20 observations on the response variable \\( y \\) along with the predictor variables \\( x_{1} \\) and \\( x_{2} \\). Click here for the Excel Data File a. Estimate a regression model with the predictor variables \\( x_{1} \\) and \\( x_{2} \\), and then extend it to also include the interaction variable \\( x_{1} x_{2} \\). What is the estimated regression coefficient for the predictor variable \\( x_{1} \\) and \\( x_{2} \\) in both models? Note: Negative values should be indicated by a minus sign. Round your answers to 2 decimal places. b-1. Which is the preferred model for making predictions