The distributions of medical costs are often skewed to the right because small numbers of patients use large amounts of health care resources. Using data from a study of colon cancer costs, we show, by example, the impact and magnitude of outliers and influential observations on health care costs and compared the effects of statistical costing methods for addressing the disproportionate influen...

Influential observation is one which either individually or together with several other observations has a demonstrably large impact on the values of various estimates regression coefficient. It been suggested by some authors that multicollinearity should be controlled before attempting to measure influence data point. In using ridge mitigate effect multicollinearity, there arises problem choos...

Influential observations do posed a major threat on the performance of regression model. Different influential statistics including Cook’s Distance and DFFITS have been introduced in literatures using Ordinary Least Squares (OLS). The efficiency these measures will be affected with presence multicollinearity linear regression. However, both problems can jointly exist New diagnostic based Two-Pa...