Difference between revisions of "Proportional"
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==Key Stage 4== | ==Key Stage 4== | ||
===Meaning=== | ===Meaning=== | ||
| − | When two [[variable]]s are [[proportional]] | + | When two [[variable]]s are [[proportional]] their values have a constant [[ratio]]. |
===About Proportional Graphs=== | ===About Proportional Graphs=== | ||
Revision as of 15:12, 5 December 2021
Key Stage 4
Meaning
When two variables are proportional their values have a constant ratio.
About Proportional Graphs
- A scatter graph showing a proportional relationship has a linear gradient.
- On a proportional scatter graph when one variable increases, the other increase or when one increases the other decreases.
- A proportional graph may have a non-zero y-intercept.
- If the line of best fit has a y-intercept of zero then it is called 'directly proportional'.
Examples
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| This scatter graph shows a linear relationship that is proportional where x increases, y increases.
\(y = mx + c\) Where m, the gradient, is positive. |
This scatter graph shows a linear relationship that is proportional where x increases, y decreases.
\(y = mx + c\) Where m, the gradient, is negative. |
This scatter graph shows a linear relationship that is directly proportional where x doubles, y doubles.
\(y = mx\) Where m, the gradient, is positive. |