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. Using PHStat, construct a regression model using all three independent variables.
b. Test the significance of each independent variable using α = 0.05.
c. Interpret the p value for each independent variable.
d. Construct a 95% confidence interval for the regression coefficients for the ICU variable and interpret the meaning.