Organics may consist of materials such as biosolids, timber, forestry residuals, manure or abattoir waste. Such analyses typically requires estimates of the probability distributions for the residuals. One application of normality tests is to the residuals from a linear regression model. Pagan test, which performs an auxiliary regression of the squared residuals on the independent variables. Another approach to bootstrapping in regression problems is to resample residuals. The residuals for a parabolic model can be calculated via formula 16. Raw residuals are one option; another is studentized residuals (in linear regression). The errors (as measured by the residuals) at the highest level are uncorrelated. The plots of the scaled residuals from the two models appear below. Payments from these organizations to performing artists are known as residuals and performance royalties. It is essential to monitor chlorine residuals in the distribution system. The squared residuals formula 17 in turn estimate formula 18. To determine whether the levels of antibiotic residuals are within regulatory requirements, special tests exist. PFAS are also found in paper mill residuals, digestates, composts, and soils. Its adequacy could be verified by the detailed measurement residuals.