12.63 Theory exam–practical exam correlation A report summarizing scores for students appearing in a theory examination x and a practical examination y states that x = 270, y = 360, sx = 60, sy = 80, and r = 0.60.

a. Find the slope of the regression line, based on its connection with the correlation.

b. Find the y-intercept of the regression line (Hint: Use its formula in Section 12.1) and state the prediction equation.

c. Find the prediction equation for predicting the results of the theory examination using the results of the practical examination.