The manufacturer of Beanie Baby dolls used quarterly price data for 20051- 2013 IV (t 1,.., 36) and the regression equation Pt = a + bt + c1D1t + c2D2t + c3D3t to forecast doll prices in the year 2014. Pt is the quarterly price of dolls, and DEPENDENT VARIABLE IPT | R -SQUAREF-RATIO P-VALUE ON 7634 0 0001 OBSERVATIONS 36 0 9078 PARAMETER STANDARD ESTIMATE ERROR 240 0 800 -8.0 -6.00 -4.0 P-VALUE 0 0005 00022 00043 0 0022 0 0001 T-RATIO VARIABLE 3 87 620 0 240 2 60 1.80 0 60 -308 -3 33 -667 D1 D2 03 What is the estimated intercept of the trend line in the 4th quarter? a. 22.8 b. 18 c. 20 d. 16 e. none of the above