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## Statistics and probability

### Course: Statistics and probability>Unit 2

Lesson 2: Describing and comparing distributions

# Example: Comparing distributions

AP.STATS:
UNC‑1 (EU)
,
UNC‑1.N (LO)
,
UNC‑1.N.1 (EK)
,
UNC‑1.O (LO)
,
UNC‑1.O.1 (EK)
Compare distributions using the features of shape, center, spread, and outliers.

## Want to join the conversation?

• Wouldn't the final round have the higher center since, as far as swim times are concerned, the smaller the time it took to finish race --the better.

Or does higher always refer to the larger of the two regardless of context?
• I think Sal misinterpreted the data at . Finalists did swim faster than semifinalists because less time means faster. But I think saying higher center for finalists is ok. We just need to be careful about how we interpret data because more isn't always better.
• I think there is a problem with the structure of this section. We are not introduced to mean/median/deviation, yet we're expected to be able to calculate it.
• i believe mean is found by adding all the data points and dividing to find the average, while median is the point in the middle most or between the middle 2 points. (i just watched a bunch of videos since i didn't find this stuff here either)
• I still don't understand the concept. Could you try explaining it in the comments so I can get a better understanding?
• Okay, so what we do in this is basically seeing what data set has a higher mean or median, or range and mean absolute deviation. We calculate those then you answer the question.
• when would you know to use mean or median for the center? would there be a reason to use one instead of the other?
• they seem to have forgotten to introduce box plots in this unit even though the quiz asked for an interpretation of one.
• What is standard deviation?
• I watched this video three times and i didn't understand it
• Sal got it backwards, I think, and the final round would have the higher center.
• So I'm still confused. Could this be explained in the comments?
(1 vote)
• There is no new concept introduced in this video. Instead, we just use our recently acquired knowledge on "Shapes of distributions" and "Clusters, gaps, peaks & outliers" to compare two distributions.

As a side note, comparing distributions is at the heart of controlled experiments like those testing new drugs efficacy (compared against a placebo) or new keyboard layout design (compared against a QWERTY keyboard).
• Wouldn't the final round have the higher center since, as far as swim times are concerned, the smaller the time it took to finish race the better.
• What about the temperature one?