Psychological response of ?re?ghters. Refer to the Journal of Human Stress study of ?re?ghters, Exercise 5.5 (p. 264). Consider using the qualita- tive variable, level of social support, as a predictor of emotional stress y. Suppose that four social support levels were studied: none, low, moderate, and high.
(a) Write a model for E(y) as a function of social support at four levels.
(b) Interpret the β parameters in the model.
(c) Explain how to test for differences among the emotional stress means for the four social support levels.