Question

Suppose that
14
inches of wire costs
70
cents.
At the same rate, how much (in cents) will
9
inches of wire cost

Answer 1

Put your information into a ratio 
14 : 70 (wire : cost) 

Change the amount of wire to 9

14/14 : 70/14
1 : 5
1 X 9 : 5 X 9 
9: 45 

Therefore 9 inches of wire costs 45 cents :)