Center, spread, and shape of distributions — Harder example
About this video
An instructor works through a range problem about five extension cords. The range is the highest length minus the lowest, so with a seven-foot range and a six-foot lowest cord, the greatest possible length x solves x minus 6 equals 7, giving x equal to 13. The video is short, so the checks focus on the definition and the algebra.
You'll be able to
- define the range of a data set as the highest value minus the lowest.
- set up and solve an equation for the greatest possible unknown value.
- explain why the unknown should be the highest value when maximizing.
Key words
- Range
- The highest value in a set minus the lowest value.
- Greatest possible value
- The largest value an unknown can take while still meeting the constraints given.
- Equation
- A statement that two expressions are equal, which can be solved for an unknown.
Transcript
- [Instructor] We're told a store has five different lengths of extension cords for sale as shown in the table above or to the left. If the range of lengths of the five cords is seven feet, what is the greatest possible value of x? Pause this video, and try to figure that out.
Well, let's just remind ourselves what the range is. The range is going to be equal to your high value minus your low value. And we want to maximize, we want to figure out the greatest possible value of x. So let's just assume that our high value here is x. And then what's going to be our low value?
Well, our low value is this six feet right over here. And then we know that the range is seven feet. And so we get seven is equal to x minus six. You could add six to both sides, and you would get that x is equal to 13. That's the greatest possible value of x.
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