Problem 3. [3 {3 {3 (3 Suppose you have a data set of six data points, with two data points at each of three different as values, a: = 5,2: = 10, and as = 15 (That is, we have 9:;- E {5,5,10,10,15,15} for 2' = 1,. ..,6). Show that the least squares regression line tted to these six data points is identical to the least squares regression line tted to the three points (5,51), (10,?2), (15,33) where 31, g, 33 represent the means of the two y values at each of the a: values