A county has four major hospitals: 1) Regional Memorial; 2) General; 3) Charity; and 4) City. A multiple regression model is used to compare the time spent in the hospital after a heart by-pass surgery among the four hospitals. The response (dependent) variable is the amount of time spent in the hospital (in days). The variables used to predict the time spent in the hospital include the patient's age, cholesterol level (in mlg.), blood pressure, as well as variables indicating the hospital in which the surgery was performed. Determine the total number of independent variables in the multiple regression model. Indicate how many of these are quantitative variables and how many are indicator (dummy) variables