Correlation analysis of the data shows the presence of some linear relationship between Y and each of the predictor variables, except 2 X . Further, there is somewhat strong positive linear relationship between any pair of the variables 1 X , 3 X , 4 X , and 5 X . These linear associations among the predictor variables are likely to pose multi-collinearity problems. The summary of the fitted regression of Y on the five predictors is shown in Table 4.