create_profiles_cluster
                        Create profiles of observed variables using
                        two-step cluster analysis
detect_outliers         Identifies potential outliers
estimate_r_squared      Estimates R^2 (r-squared) values for a range of
                        number of profiles
pisaUSA15               student questionnaire data with four variables
                        from the 2015 PISA for students in the United
                        States
plot_profiles           Return plot of profile centroids
print.prcr              Prints details of prcr cluster solution
summary.prcr            Concise summary of prcr cluster solution
