The data for this problemare taken from a 1987 article by Irwin et al., entitled “Life events, depressive symptoms, and immune function,” published in the American Journal of Psychiatry. Thi

The data for this problemare taken from a 1987 article by Irwin et al., entitled “Life events, depressive symptoms, and immune function,” published in the American Journal of Psychiatry. This article published resultsof a cross-sectional study of the relationship between major life events and immune function. Subjects in the study included women whose husbandswere undergoing treatment for metastatic lung cancer, women whosehusbands had died of lung cancerin the preceding 1-6 months, and women whose husbands were in good health. Scores for the Social Readjustment Rating Scale (SRRS) were recorded for each of the women; in addition,a measure of immune system function, natural killer (NK) cell activity,was determined. Women were divided into three groups depending on their scoreson the SRRS: those with low scores (54 or less), those with moderatescores (55-99), and those with high scores (100 or more). The file IRWINb.SAS, available on blackboard, contains the naturalkiller cell activity (lytic units) for 37 women in the study, classified by their SRRS scores. Use and augment this fule to answer the questions below.
Generate the NK sample means and standard deviations for the three groups.(0.5 pt)
Using the log-transformed NK scores (these are obtainedin IRWIN.SAS), get the sample means and standarddeviations for the three groupsof the log-transformed NK variable.(0.5 pt)
Considering your resultsfrom (a) and (b), which scale (raw or log-transformed) better satisfies the assumptions of the one-way ANOVA? (0.5 pt)
Depending on what you decide in (c), use the data to construct the appropriate ANOVA table. (3 pts)
Test the hypothesis that there are no differences in the mean natural killer cell activity values (either raw or log)for these three groups. (0.5 pt)