A least-squares multiple linear regression model was fit on 24 observations. The resulting regression equation is given by y = 65 + 29 x1 + 16 x2 - 54 x3 Calculate the percent of variance in y explained by x1 and x2 and x3 together. SS df MS F-statistic Regression Residual 147 Total 183 6.55749% 4.016496 19.67219% 66.20699% 1.632796