To fit a statistical model to a life data set, parameters for making the life distribution most closely fit the data are estimated. Although there are several estimation methods to choose from, based on the data type and number of data points being analysed, various forms of rank regression and Maximum Likelihood Estimation (MLE) are used most frequently. This is because only they work with all data types and for all distributions. Based on the parameter estimations, the resulting Weibull probability plot indicates how well the selected distribution fits the data set being analysed.