Recent research into the cost of various medical procedures has shown the impact of certain complications encountered in surgery on the total cost of a patient's stay in the hospital. The researchers used regression analysis and found the following results: Total cost for patient = Constant, plus aLength of stay (measured in days), plus b* Presence of one or more complications (= 1 if true, O if false), plus c* Use of a laparoscope = 1 if true, O if false) where a, b, care coefficients of the regression model. The laparoscope is an instrument somewhat like a miniature telescope with a fiber optic system that brings light into the abdomen. It is about as big around as a fountain pen and twice as long. The research, based on 63 patients, showed the following regression results: R-squared: 56% Constant term: $3,158 Coefficients and t-values for independent variables: Coefficient t-value Length of Stay $ 887 7.51 Complications $ 1,912 5.30 Laparoscope $ 928 2.26 Required: 1. What is the estimated cost for a patient whose surgery has complications and who stays in the hospital 4 days, and whose surgery requires a laparoscope? Estimated cost 2. Which, if any, dummy variables are used in this regression? (You may select more than one answer. Single click the box with the question mark to produce a check mark for a correct answer and double click the box with the question mark to empty the box for a wrong answer. Any boxes left with a question mark will be automatically graded as incorrect.) Complications were present Length of stay (measured in days) Use of a laparoscope