This guide is for analyzing mediating or intervening variables and factors. Go to Confirmatory Factor analysis notes (QuickGuideConfirmatory) to get to this point. We are going to treat Factor 3 as the mediating (or treatment, or intervention) variable.
Double click F2 to get the following.
Double click one of the parameters to get the following.
Chi square with the (f3,f1)=(f2,f1) is 115.165. The full model is 109.86 and the difference is 5.305 and significant at <.05 (3.84).