5. The demand function for a good is Q = a - bPx + cM + e Here Px is the price of the good X and M is income. Least square regression indicates that a-5.25, -1.46,-21, da 6.2,06 = 0.56, =0.05 The R-squared is 0.24. a. Compute the t-statistic for b and of the estimated coefficients. b. Determine which (if any) of the estimated coefficients are statistically different from zero. c. Explain, what the R-square in this regression indicates.