Answer:
b) Y =5.73X +4.36 
C) =5.73225*(21)X +4.359
 124.73625 
 D) 163.728 = 5.73X +4.36 
 X = (163.728 - 4.36)/5.73
 X = 27.81291449 
 Year would be 2027
Explanation:
x1 y1 x2 y2 
4 27.288 16 96.075 
 
 (Y2-Y1) (96.075)-(27.288)= 68.787 ΔY 68.787 
(X2-X1) (16)-(4)= 12 ΔX 12 
 
slope= 5 41/56 
B= 4 14/39 
 
Y =5.73X +4.36