About this video
A table gives the number of tomatoes needed for different servings of spaghetti bolognese. The video simplifies each ratio of tomatoes to servings and finds they all equal 5 to 3, so the relationship is proportional.
You'll be able to
- test whether ratios in a table are equivalent by simplifying them.
- decide that a relationship is proportional when every ratio is the same.
Key words
- equivalent ratios
- Ratios that simplify to the same ratio, like 10 to 6 and 5 to 3.
- proportional relationship
- A relationship where the ratio of the two quantities is always the same.
Transcript
The following table describes the relationship between the number of servings of spaghetti bolognese-- I don't know if I'm pronouncing that-- or bolognese, and the number of tomatoes needed to prepare them. Test the ratios for equivalents, and determine whether the relationship is proportional.
Well, you have a proportional relationship between the number of servings and the number of tomatoes is if the ratio of the number of servings to the number of tomatoes is always the same. Or if the ratio of the number of tomatoes to the number of servings is always the same.
So let's just think about the ratio of the number of tomatoes to the number of servings. So it's 10 to 6, which is the same thing as 5 to 3. So here the ratio is 5 to 3. 15 to 9, if you divide both of these by 3, you get 5 to 3. So it's the same ratio. 15 to 25, if you divide both of these by 5, you get 5 to 3.
So based on this data, it looks like the ratio between the number of tomatoes and the number of servings is always constant. So yes, this relationship is proportional.
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