EXERCISE 4 Consider the regression model Eli = (50 + 5137?) + 51(301' If) + 61' This model is called the centered version of the regression model yi : g + lm + 61' that was discussed in class. If we let 70 = g + loc we can rewrite the centered version as yi = 70 +1(;1':z f) + 61'. Find the least squares estimates of '70 and l