City Hospital would like to develop a regression model to predict the total hospital bill for a patient based on his or her length of stay, number of days in the hospital’s intensive care unit (ICU), and age of the patient. Data for these variables can be found in the Excel file City Hospital.xlsx.

a. Construct a regression model using all three independent variables.

b. Calculate the multiple coefficient of determination.

c. Test the significance of the overall regression model using α = 0.05.

d. Calculate the adjusted multiple coefficient of determination.