Question

Laine was helping wash cars to raise money for her school's Mandarin Club. Her job was to wash the wheels of the cars. The table below shows the number of wheels she washed, along with the number of dollars the club earned.

Wheels Dollars
4 7
8
12 21
16 28
24

What pair of numbers are needed to complete the table correctly?

Answer 1

the 3rd and 4th rows show that the slope is (28-21)/(16-12) = 7/4
So y = 7/4 x
or, just note that on the left you count by 4's, and on the right you count by 7's