ANOVA / ANCOVA

A researcher has collected data on hospital patient satisfaction. He wants to fit an appropriate regression model to the satisfaction response using age and severity as the

regressors and account for the medical (1) versus surgical classification (0) of each

patient with an indicator variable.

Use the SAS output to answer the following questions.

(a)Write an appropriate regression model for this data.

(b) Specify appropriate null and alternate hypotheses for testing the adequacy of the overall model. Report values for the F-statistic, degrees of freedom, and p-value, and state the conclusion of this test.

(c) Is there any evidence to support a claims that medical and surgical patients differ in their satisfaction?

(d). Write the equation of the least squares regression "line" for this model.

(e). Report the R² value and give an interpretation of this value in the context of the problem.

The REG Procedure Model: MODELI Dependent Variable: Satisfaction Number of Observations Read 25 Number of Observations Used 25 Analysis of Variance Sum of Mean Source DF Squares Square F Value Pr > F Model 3 8791.51792 2930.50597 30.17 <.0001 error corrected total root mse r-square dependent mean adj r-sq coeff var parameter estimates standard variable df estimate t value pr> t Intercept 139.77328 8.25075 16.94 <.0001 age severity surg med>