<h3>Solution :</h3>

By cross multiply, we get






Therefore, answer is 
divide total paid by number of pencils for price of 1 pencil
4.50 / 18 = 0.25 for 1
so you would put a dot at (1, 0.25) (2,0.5) (3,0.75) etc and draw a line through the dots
see attached picture:
68 because it is a perpendicular bisector we can assume that the angles full length is 90 degrees meaning you can just do 90-22=68
Answer:
I believe the answer is 0.3