Fixsy)ニメーーツ coustalaト: xty?こ4

What should we do when we have (imperfect) multicollinearity? Drop some of the independent variables. Add more independent variables in order to reduce multicollinearity. Consider testing whether the highly collinear variables are jointly significant. O Ignore it no matter what.

Find the least squares approximating squares error for the points (1.1), (4.3). line and the least (2, 2), (3.2), and

A motorist found that the efficiency of her engine could be increased by adding lubricating oil to fuel. She experimented with different amounts of lubricating oil and the data are Amount of lubricating oil (ml) Efficiency (%) 0 25 50 75 100 | 60 70 75 81 84 (a) Obtain the least squares fit of a straight line to the amount of lubricating oil. (b) Test whether or not the slope B, = 0. Take a = 0.05 as your level of significance. (c) Construct a 90% confidence interval on the mean response at xo = 10 ml.