You are required to setup a predictive equation involving variable 1 and variable 2. First, you plot the DATA to determine if linear regression applies. You decide Linear regression is not applicable because it appears that there are two linear patterns indicating that the data come from two populations. The linear regression equation will be very useful because the points have a strong linear pattern. You need more information before deciding to use linear regression. Linear regression is not useful because the points have no discernible pattern. Linear regression is not applicable because the point pattern is curvilinear (has a curve).