Regression methods were used to analyze the data from a study investigating the relationship between roadway surface temperature ( x) and pavement deection ( y). Summary quanti ties were 71 = 20, 2:1 yi = 12 _7, 2:1 y? = 88, 2:1 :31 = 1487 , 2:1 3312 = 143,215, 211:1 33iyi = 1083. (a) Calculate the least squares estimates of the slope and intercept. Graph the regression line. (b) Use the equation of the fitted line to predict What pavement deection would be ob served when the surface temperature is 85 OF. (c) What is the mean pavement deflection when the surface temperature is 90 OF? (d) What change in mean pavement deflection would be expected for a 1 F change in surface temperature