About Direct Proportion Formula
A mathematical comparison between two numbers in which the ratio of the two numbers equals a fixed value is known as direct proportion. When two ratios are equal, they are in proportion, according to the proportion definition. The proportions are represented by the symbol "∝".
Direct Proportion Definition
"When the relationship between two quantities is such that if we increase one, the other will also rise, and if we decrease one, the other will similarly decrease, then the two values are said to be in a direct proportion," according to the definition. For example, suppose there are two values x and y, where x represents the number of candies and y represents the total amount of money spent. We will have to spend more money if we buy more candy, and we will pay less money if we buy fewer candies. As a result, we can argue that x and y are directly proportional. x ∝ y is the symbol for it. Direct variation is another name for direct proportion. More Maths Formulas on the parent's page.
- Real-life examples of direct proportionality are as follows:
- The overall amount of money spent is directly proportionate to the number of food products purchased.
- The amount of labour done is related to the number of workers.
- About a fixed time, speed is proportional to distance.
Direct Proportion Formula and use
The direct proportion formula says if the quantity y is in direct proportion to quantity x, then we can say y = kx, for a constant k. y = kx is also the general form of the direct proportion equation. y ∝ x => y = kx
where,
- k is the constant of proportionality.
- y increases as x increases.
- y decreases as x decreases.
Solved Example of Direct Proportion Formula
Sol:
- Using the direct proportion formula,
- y = kx
- Substitute the given x and y values, and solve for k.
- 36 = k × 6
- k = 36/6 = 6
- The direct proportion equation is: y = 6x
- Now, substitute x = 80 and find y.
- y = 6 × 80 = 480
- Answer: The value of y is 480.
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