13.15 The file Daylight in the Seasons folder of the CD contains hours/weekday of exposure to daylight for the oldest group of subjects in the Seasons study. This was of interest to the researchers because it is believed that exposure to daylight affects mood.

(a) Perform an ANOVA on the female (i.e., sex=1) DIRWDC (Direct exposure to daylight during weekdays) scores; 1=winter, 2=spring, 3=summer, and 4=fall.

(b) Calculate the partial Ȧ2 for the effects of Seasons.

(c) Perform a trend analysis.