Main content

## SAT

### Unit 10: Lesson 3

Problem solving and data analysis- Ratios, rates, and proportions — Basic example
- Ratios, rates, and proportions — Harder example
- Percents — Basic example
- Percents — Harder example
- Units — Basic example
- Units — Harder example
- Table data — Basic example
- Table data — Harder example
- Scatterplots — Basic example
- Scatterplots — Harder example
- Key features of graphs — Basic example
- Key features of graphs — Harder example
- Linear and exponential growth — Basic example
- Linear and exponential growth — Harder example
- Data inferences — Basic example
- Data inferences — Harder example
- Center, spread, and shape of distributions — Basic example
- Center, spread, and shape of distributions — Harder example
- Data collection and conclusions — Basic example
- Data collection and conclusions — Harder example

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# Center, spread, and shape of distributions — Harder example

Watch Sal work through a harder Center, spread, and shape of distributions problem.

## Want to join the conversation?

- How is this the harder example? This is the easiest one in all of the questions.(63 votes)
- They probably mean it's harder by how the question is worded.(10 votes)

- what are center, spread and shape of distributions,?(6 votes)
- Center is exactly what the name implies, it's the middle or average value of a data set. Mean and median are the two best measures of center. You should use mean when there aren't any outliers, extremely high or low values, as mean can be affected by outliers, changing the mean that you get. Median should be used when there aren't any outliers, as median doesn't change by a large amount.

Spread is the size of a data set. Interquartile Range(IQR) and Standard Deviation are the two best measures of center. IQR can be used when there are no outliers and it can be found by subtracting Quartile 3 and Quartile 1, which are two values in a boxplot. Standard Deviation is hard for me to explain but it's easy enough to look up. Sorry about that. You should only use standard deviation if there aren't any outliers.

Hope that helped! :)(19 votes)

- Just a heads up to avoid confusion... The 18 he wrote should have been an 8. He accidentally added a 1 and then forgot to take it out(11 votes)
- Yes sjeremiah2003, this is the mistake. It should be 8 instead of 18. We can ignore this mistake.(1 vote)

- I hope all questions in the sat are like this. I will get a perfect score(9 votes)
- the easiest way to do this is just add the lowest number in the series with the range and you will get x because lowest no-highest no=range(8 votes)
- the easiest way to do this is just add the lowest number in the series with the range and you will get x because lowest no-highest no=range(5 votes)
- guys the 18 is actually 8 he wrote it but accidentally added one in front of it so don't mind that plus you don't need to consider that part cause u are adding 6+7= 13 so good luck(5 votes)
- how come what sal solved is nothing like the practise(4 votes)
- why didn't we do (8+11+6+7+x)/5=7 and just find x=3 ?(3 votes)
- why didnt they just add the lower number(3 votes)
- I'm not sure what you mean, but maybe because it says what's the
**greatest possible**value of x? in the question...(1 vote)

## Video 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.