22.17. Refer to Eye contact effect Problem 19.12. Age of personnel officer is to be used as a con- comitant variable. The ages (Xijk) of the personnel officers follow. i = 1 i = 2 j=1 j=2 j=1 j 42 51 43 42 30 35 53 47 ... 35 49 49 56 a. Obtain the residuals for covariance model (22.26). b. For each treatment, plot the residuals against the fitted values. Also prepare a normal prob- ability plot of the residuals and calculate the coefficient of correlation between the ordered residuals and their expected values under normality. What do you conclude from your analysis? c. State the generalized regression model to be employed for testing whether or not the treat ment regression lines have the same slope. Conduct this test using = alternatives, decision rule, and conclusion. What is the P-value of the test? .005. State the Eye contact effect. In a study of the effect of applicant's eye contact (factor A) and personnel officer's gender (factor B) on the personnel officer's assessment of likely job success of applicant, 10 male and 10 female personnel officers were shown a front view photograph of an applicant's face and were asked to give the person in the photograph a success rating on a scale of 0 (total failure) to 20 (outstanding success). Half of the officers in each gender group were chosen at random to receive a version of the photograph in which the applicant made eye contact with the camera lens. The other half received a version in which there was no eye contact. The success ratings follow. Factor B (gender of officer) Factor A j=1 j=2 (eye contact) Male Female =1 Present 11 15 7 12 10 16 i=2 Absent 12 14 16 17 ... 14 18 Yijk = .. +; +; + ()ij + y (Xijk ..) + ijk i = 1, ..., a; j = 1. . . ., b; k = I, ..., n (22.26)