It would approximately be $9.07
12 of them are black
2 of them is yellow
2 of them are both
M=(6-1)/(8-5)=5/3
y=5x/3+b, using (5,1)
1=25/3+b
b=-22/3
y=(5x-22)/3
...
m=(8-3)/(-1--4)=5/3...
y=5x/3+b, using (-1,8)
8=-5/3+b
b=29/3
y=(5x+29)/3
Since they have the same slope and difference y-intercepts they are parallel lines and will never intersect.