Key Stage 4
Meaning
When two variables are directly proportional when one variable is multiplied by a factor, the other variable is multiplied by the same factor.
About Direct Proportionality
- A scatter graph showing a directly proportional relationship has a linear gradient that passes through zero, it has a y-intercept of zero.
- On a proportional scatter graph when one variable doubles, the other doubles or when one triples the other triples.
Examples
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This scatter graph shows a linear relationship that is directly proportional where x doubles, y doubles.
\(y = mx\) Where m, the gradient, is positive. |