Proportional Relationship
Checker

Is This Graph Proportional? Checker

Enter points or values to check whether a graph shows a proportional relationship and why.

Line through (0,0) and all y÷x = k

Two conditions for a proportional graph

Enter points as x,y separated by spaces

How to use this checker

Enter at least two points from the graph. The checker tests whether the line passes through (0,0) and whether all y÷x ratios match.

What this means in math class

Teachers ask two questions: is the line straight, and does it go through the origin? This checker automates both tests.

Worked examples

Example 1: Proportional graph

Points: (0,0), (2,6), (4,12)

  1. Step 1:Check origin: first point is (0,0) ✅
  2. Step 2:Check ratio: 6÷2 = 3
  3. Step 3:Check ratio: 12÷4 = 3
  4. Step 4:All ratios equal 3 ✅
Answer: ✅ This graph IS proportional (k = 3)

Example 2: Non-proportional graph

Points: (0,2), (2,8), (4,14)

  1. Step 1:Check origin: first point is (0,2) ❌
  2. Step 2:Not through the origin
  3. Step 3:Relationship is linear but not proportional
Answer: ❌ This graph is NOT proportional (not through origin)

Frequently asked questions

What makes a graph proportional?

A straight line that passes through the origin (0,0).

Can a curved line be proportional?

No. Proportional graphs are always straight lines.

Related tools

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