According to the American Psychiatric Association, posttraumatic stress disorder (PTSD) is a common psychological consequence of traumatic events that involve threat to life or physical integrity. A. Ehlers et al. studied various characteristics of political prisoners from the former East Germany and presented their findings in the paper €œPosttraumatic Stress Disorder Following Political Imprisonment: The Role of Mental Defeat, Alienation, and Perceived Permanent Change€ (Journal of Abnormal Psychology, Vol. 109, Issue 1, pp. 45€“55). Current severity of PTSD symptoms was measured using the revised Impact of Event Scale. Following are summary statistics for samples of former prisoners diagnosed with chronic PTSD (Chronic), with PTSD after release from prison but subsequently recovered (Remitted), and with no signs of PTSD (None).

At the 5% significance level, do the data provide sufficient evidence to conclude that a difference exists in current mean severity of PTSD symptoms among the three diagnosis groups?
For the degrees of freedom in this exercise:

Refer to the discussion of using summary statistics in one-way ANOVA. We have provided values of Fα not given in Table VI.

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PTSD1 Chronic 32 73.0 19.2 Remitted 20 45.6 23.4 None29 34.5 22.0 α 10. 10 0.05 0.025 0.01 0.005 Fa 2.37 3. 3.87 4.89 5.68