The following table shows additional regression results presented by the researchers in the study described in Exercise 8-36. There are two regressions. The right-hand column shows the results for all patients, including those treated with laparoscopic surgery. The left-hand column shows the results for the sample of patients who were treated without the laparoscopic surgery, and the related costs.

Required
1. Which of the two regressions has the better reliability and precision in estimating cost? Why?
2. Interpret the values of each coefficient and the standard error for each coefficient.
3. What are the t-values for each of the independent variables for each regression?

1. The laparoscopic treatm ent has the better regression result, with a significantly higher R-squared and lower standard error for the number of complications variable 2-The coefficients tell us the additional cost for an increm em entin each of the independent variables. For example, the laparascopic treatm ent itself costs $908, and each day in the hospital costs S861 in the laparoscipic treatment The standard error of each independent variable is used to evaluate the stati stical reliability of the independent variable. The t-value is the ratio of the coefficient to the standard error of the independent variable 3. The t-value is the ratio of the coefficient to the stan dard error of the independent variable Not Laparoscopic 8,043 Not significant Laparoscopic Coeffici ents for In dependent Variables Intercept Length of Stay t-value t-valu e S 3,719 861 80 Coefficient Standard error for the coefficient Not applicable Number of Complications 3,393 1,986 406 Coefficient Standard error for the coefficient 1,239 2.74 4.89 Laparascopic Coefficient Standard error for the coefficient Not applicable Not applicable 908 3582.54 R-squared 0.11 0.53