Emergency services (EMS) personnel are constantly exposed to traumatic situations. However, few researchers have studied the psychological stress that EMS personnel may experience. The Journal of Consulting und Clinical Psychology (June 1995) reported on a study of EMS rescue workers who responded to the 1-880 freeway collapse during the 1989 San Francisco earthquake. The goal of the study was to identify the predictors of symptomatic distress in the EMS workers. One of the distress variables studied was the Global Symptom Index (GSI). Several models for GSI, y, were considered based on the following independent variables:

x₁ = Critical Incident Exposure scale (CIE)

x₂ = Hogan Personality Inventory-Adjustment scale (HPI-A)

x₃ = Years of experience (EXP)

x₄ = Locus of Control scale (LOC)

x₅ = Social Support scale (SS)

x₆ = Dissociative Experiences scale (DES)

x₇ = Peritraumatic Dissociation Experiences Questionnaire, self-report (PDEQ-SR)

a. Write a first-order model for E(y) as a function of , the first five independent variables, x₁-x₅.

b. The model of part a, fitted to data collected fitted to data n = 147 EMS workers, yielded the following results: R² = .469, F = 34.47,p-value

C. Write a first-order model for E(y) as a function oi all seven independent variables, x₁-x₇.

d. The model, part c, yielded R² = .603. Interpret this result

e. The t-tests for testing the DES and PDEQ-SR variables both yielded a p-value of ,001. Interpret these