A) Comment on the difference between the estimated coefficients for the pigmeat variable for the simple linear regression model and the multiple linear regression model. Do you reject the null hypothesis that pigmeat does not have an effect on the ozone in both models? Why do you observe a difference regarding the pigmeat variable in both models?

B) By looking at the scatterplot, does the variance of the error term look constant or not?

C)What is the consequence for the hypothesis testing (t-tests and F-tests) if one finds that the variance of the error term is non-constant?

Variables Entered/Removeda Variables Variables Model Entered Removed Method 1 pigmeat Enter a. Dependent Variable: ozone b. All requested variables entered. Model Summary Adjusted R Std. Error of Model R R Square Square the Estimate 1 .7112 505 472 1230.4003 a. Predictors: (Constant), pigmeat ANOVA Sum of Model Squares df Mean Square F Sig. 1 Regression 23175828.3 1 23175828.3 15.309 001 Residual 22708272.0 15 1513884.80 Total 45884100.2 16 a. Dependent Variable: ozone b. Predictors: (Constant), pigmeat Coefficients Standardized Unstandardized Coefficients Coefficients Model B Std. Error Beta t Sig. 1 (Constant) 652.529 427.554 1.526 148 pigmeat 1.053 .269 711 3.913 001 a. Dependent Variable: ozoneVariables Entered/Removeda Variables Variables Model Entered Removed Method 1 population Enter pigmeat" a. Dependent Variable: ozone b. All requested variables entered. Model Summary Adjusted R Std. Error of Model R R Square Square the Estimate 1 .970 941 933 438.5569 a. Predictors: (Constant), populatingmeat ANOVA Sum of Model Squares df Mean Square F Sig. 1 Regression 43191450.1 2 21595725.1 112.283 <.001b residual total a. dependent variable: ozone b. predictors: populationeat coefficientsa standardized unstandardized coefficients model b std. error beta t sig. pigmeat .146 .652 populati>