Constant of proportionality from graph | 7th grade | Khan Academy

less than 1m read

·Nov 11, 2024

The following graph shows a proportional relationship. What is the constant of proportionality between y and x in the graph? Pause this video and see if you can figure that out.

All right, now let's do this together and let's remind ourselves what a constant of proportionality even is. If we know that there is a proportional relationship between y and x, then there will be a constant of proportionality between these variables. What this is, is it is a number that I would have to multiply x by to get to y.

So I could make a little table here, as we often do when we describe proportional relationships. X and y. We know that when x is 0, y is 0. But if I multiply 0 by anything, I'm going to get 0.

But then when x is 1, what is y? When x is 1, y is 3. They mark it right over there. When x is 2, what is y? X is 2, we see that y is 6.

So our constant of proportionality is what are we multiplying x by to get to y? Well, let's see. To go from one to three, I have to multiply by three. To go from two to six, I have to multiply by three.

Another way to think about it is we could write the equation y is equal to something times x. The number that we multiply x by to get y is our constant of proportionality. We’ve seen in all of these situations this should be true for any point on this line. You give the x, you multiply it by 3, you get your y.

So the relationship here is y is equal to 3x, so 3 is our constant of proportionality.

One Year & 100,000 Subscribers Later (Thank You!)

The Theory of Information

View All

Curvature formula, part 5

So let’s sum up where we are so far. We’re looking at this formula and trying to understand why it corresponds to curvature, why it tells you how much a curve actually curves. The first thing we did is we noticed that this numerator corresponds to a cert…

Orca Hunt Seven Gill Sharks | Orca vs. Great White

[Music] Ingrid Visser and Ken Iscolet are looking for evidence that orcas are hunting great white sharks in New Zealand waters. Ingrid has evidence that there’s a disturbing pattern in orca hunting. New Zealand orcas are hunting sevengill sharks, just lik…

The presidential incumbency advantage | US government and civics | Khan Academy

What we’re going to do in this video is talk about the incumbent advantage. This is the idea that the person who is already in power, the incumbent, has an advantage in elections. In particular, we’re going to focus on presidential elections, although thi…

Principles for Success: “Struggle Well” | Episode 8

Principles for Success: An Ultra Mini-Series Adventure in 30 Minutes and in Eight Episodes Episode 8: Struggle Well, so far I described how I learned to confront my own realities, my problems, my mistakes, and weaknesses, and how I surrounded myself wit…

Buoyancy Quiz

We are doing a buoyancy experiment today. If you drop a golf ball into some dishwashing liquid, it sinks very slowly. So why does it sink in the detergent? Because the golf ball is more heavy than the liquid that’s in the container— then the detergent. W…

Identifying Unknown Soldiers | Ghosts of Pearl Harbor

[music playing] NARRATOR: Of the 429 men who died on the battleship “USS Oklahoma,” only 35 were identified in the years immediately following the attack. The rest were buried in graves marked “Unknown.” But almost 75 years later, one of these unknown me…

Constant of proportionality from graph | 7th grade | Khan Academy

More Articles