Test of the Randomness of Residuals and Detection of Potential Outliers for the Morgan-Mercer-Flodin Used in the Fitting of the Prediction of Cumulative Death Cases in Nigeria Due to COVID-19

In this study, we use the Wald–Wolfowitz runs test as a statistical diagnosis tool to check whether randomness of residual for Morgan-Mercer-Flodin (MMF) utilized in fitting prediction cumulative death cases Nigeria owing COVID-19. The revealed that there were 13 total runs, however number should have been expected based on randomization assumption was 26. Because p-value less than 0.05, can conclude residuals are not truly random and must reject null hypothesis. Too many instances specific run sign may indicate presence negative serial correlation; other hand, too few clustering with same or systematic bias. A further analysis using Grubb's existence an outlier, which indicates data be remodeled because outlier.