Chapter 13, Problem 44CE

A hospital emergency room analyzed n = 17,664 hourly observations on its average occupancy rates using six binary predictors representing days of the week and two binary predictors representing the 8-hour work shift (12 a.m.–8 a.m., 8 a.m.–4 p.m., 4 p.m.–12 a.m.) when the ER census was taken. The fitted regression equation was AvgOccupancy = 11.2 + 1.19 Mon − 0.187 Tue − 0.785 Wed − 0.580 Thu − 0.451 Fri − 0.267 Sat − 4.58 Shift1 − 1.65 Shift2 (SE = 6.18, R² = .094, R²_adj = .093). (a) Why did the analyst use only six binaries for days when there are 7 days in a week? (b) Why did the analyst use only two work shift binaries when there are three work shifts? (c) Which is the busiest day? (d) Which is the busiest shift? (e) Interpret the intercept. (f) Assess the regression’s fit.