Converting between measurement systems

- [Instructor] We're told a mural by Miguel Covarrubias is 20 yards long. It looks like this is the mural right over here. There are approximately 10 meters in 11 yards. Given this ratio about how long is the mural in meters? Pause this video. Have a go at that before we work through this together. All right, so we're going to compare two things in terms of both meters and yards. And so let's just set up some ratios over here. So there is first the actual mural right over here, it's going to be some number of meters, and we know that number of meters is the same thing as 20 yards, 'cause they give us its length in yards. And we also know that if I were to have something that is 11 yards long, if I were to measure it in terms of meters, it would be 10 meters. So one way to think about it is we could set, we should say that these ratios need to be equal to each other. Something that 11 yards long is 10 meters, then something that's 20 yards long, well it's going to be some number of meters that relate to 20, the same way that 10 relates to 11. So the first question I ask you is question mark going to be greater than or less than 20? Well, one way to think about it, if we look on the right side, right over here, however many yards it is, when you measure it in meters, it's a smaller number. So however many yards it is, when you measure it in meters, it's a smaller number. So first of all, this is going to be less than 20 meters. Now let's try to estimate what that might be. So the measure in meters, and when I look at 10/11 is one way to think about it. That's about a little over 90%. It's like 90, 91%. If I were to take 10 divide it by 11, it's gonna be 0.9 something, 0.90 something I think. And so if I were to take a similar part of 20, I would get something in the range of a little over 18. So I would say this is going to be approximately 18 meters. I could get a calculator out and calculate this exactly, but this is going to be a pretty good approximation.