Can someone please explain what direct proportion means and give real-life examples?

Question

Julia Adams · Accepted Answer

An increase in one quantity causes a proportional increase in another quantity.

In a direct variation, there is a comparison between two quantities and an increase in one causes a proportional increase in the other. This concept occurs in every part of our daily lives. More people will eat more food. Buying more packets will cost more money. More petrol in a tank means you can drive a longer distance, More people working together can do more work. A bigger roast of meat will take a longer time to cook. A person with a big stride will cover more distance with the same number of paces. A heavier parcel will cost more money to send by post. More people to be transported will require more buses. Baking more cakes requires more ingredients. and so on..... In each case there is a constant ratio between the two quantities. (double one, double the other)

Ethan Adkins · Answer

undefined Direct proportion means that as one quantity increases, the other quantity also increases at a constant rate, or as one quantity decreases, the other quantity decreases at a constant rate.

Real-life examples of direct proportion include:
1. The more hours you work, the more money you earn (assuming a constant hourly wage).
2. The more ingredients you use in a recipe, the more food you can make.
3. The more fuel you put in a car, the farther it can travel (assuming a constant fuel efficiency).
4. The more pages you read per day, the faster you finish a book.
5. The more employees you hire, the higher the total salary expenses will be (assuming equal salaries per employee).