Step by step
The question
Question: is this table proportional: x is 2, 3, 5, and y is 6, 9, 16?
x: 2, 3, 5; y: 6, 9, 16
Proportional means: y divided by x is always the same number.
We call that number k.
Then y = k times x.
proportional: y ÷ x is always the same
k = y ÷ x, y = kx
We write it as a table.
1 Divide y by x
For each pair we work out y divided by x.
6/2 is 3.
9/3 is 3.
16/5 is 3.2.
= 62 = 3, 93 = 3, 165 = 3.2
2 Compare the answers
The answers are not the same.
So it is not proportional.
= not the same → not proportional
3 Check
Let's check: the first two pairs already give different answers.
So the answer is right!
6 ÷ 2 ≠ 9 ÷ 3
Let's look back.
First: divide y by x.
Then: compare the answers.
Last: check.
Answer
= not the same → not proportional