Graphing proportional relationships from a table
About this video
Sal graphs a proportional relationship from a table by plotting (0, 0) and (6, 1), points with whole-number coordinates. He then finds the slope as change in y over change in x: 1/6.
You'll be able to
- choose easy points from a table to graph a proportional relationship.
- find the slope as change in y over change in x.
Key words
- proportional relationship
- A relationship where y is always the same multiple of x, and (0, 0) is on the graph.
- slope
- The change in y divided by the change in x.
Transcript
We're asked to graph the proportional relationship shown in the table below. And they give us a table of x values, and the corresponding y values. So we see when x is equal to 0, y is equal to 0. Then they give us a bunch of other points. When x is 3, y is 0.5.
When x is 6, y is 1, so on and so forth. So let's graph one of these that actually have integer values for both coordinates. So when x is 6, y is 1. So we only need two points to specify the line. So we've actually graphed it. But then they also ask us, what is the slope of this line?
And we just have to remind ourselves. Our slope is what is our change in y for a given change in x. So, for example, or another way to think about it, what is your change in y over your change in x? So here, our x changed by 6. It went from 0 to 6. And our y changed by 1.
So our change in y over our change in x, which is the definition of slope, our change in y is 1, when our change in x is 6. See that right over here. Change in y, 1 when our change in x is 6. Let's check our answer. We got it right.
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