a) Construct a linear regression models between: 1. Y and x1 2. Y and x2 3. Y and x3 4. Y and x4 5. Y and x5 6. Y and x6 7. Y and x1,x2,x3,x4,x5,x6 b) Write a suitable hypothesis for each model and test these hypothesis c) Which model performs biter than others why and how