the line is not linear so explain how to do this: If the relationship is not strictly linear, you might consider centering the covariate (age at rehab). This involves subtracting the mean age at rehab from each individual's age at rehab. This can help reduce multicollinearity if you plan to include interaction terms in your model. Remember, the interpretation of your results should be based on the data and the context of your research question on sass if the instuctuons saiid Scatter Plot and Linearity: To create a scatter plot in SPSS, go to Graphs > Scatter/Dot. Select "Simple Scatter" and define your variables. The scatter plot will show you the relationship between age at rehab and the outcome variable Post_6mnwalk, as it measures the effectiveness of the rehabilitation. If the points form a straight line, the relationship is linear. If not, the relationship is not strictly linear