For all significance tests, use a = 0.05 significance level. Q.1. A study was conducted to relate available coefficient of friction (Y, ACOF) for 58 models of shoes (n = 1 16 total measurements) to the following predictor variables for the regression model: E ( Y } = Bo + BIX, + B2X 2 + By X3 + BAXA Heel shape: X1 = 1 if Beveled, 0 if flat-edged Floor surface: X2 = 1 if ceramic, 0 if laminate . . Tread surface area: X3 (cm?) Material hardness: X4 measured with a durometer SUMMARY OUTPUT .Regression Statistics Multiple R 0.933 R Square Adjusted R Square 0.866 Standard Error 0.055 Observations 116 ANOVA af SS MS F F (. 05) Regression 2.2673 Residual 0.3358 #N/A #N/A Total 115 2. 6031 #N/A #N/A #N/A Coefficientsandard Err t Stat P-value Intercept 0.223 0.081 2.753 > or or <.05 x2> or or or