math: make grouped data quartiles accurate

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eggy 2020-09-29 12:22:58 -04:00
parent 68f1e9493d
commit 23c9b28a30

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@ -97,9 +97,7 @@ The first and third quartiles are the median of the **[minimum, median)** and **
When working with grouped data given in ranges, the actual data is unavailable. The five numbers above are instead: When working with grouped data given in ranges, the actual data is unavailable. The five numbers above are instead:
- The minimum value is now the lower class boundary of the lowest class. - The minimum value is now the lower class boundary of the lowest class.
- The first quartile is the midpoint of the class it resides in. - The first and third quartiles, as well as the median, are now found by guesstimating the value on a cumulative frequency curve.
- The median is the midpoint of the class it resides in.
- The third quartile is the midpoint of the class it resides in.
- The maximum value is now the upper class boundary of the highest class. If the highest value is excluded (e.g., $90≤x<100$), it also must be excluded when representing data (e.g., open dot instead of filled dot). - The maximum value is now the upper class boundary of the highest class. If the highest value is excluded (e.g., $90≤x<100$), it also must be excluded when representing data (e.g., open dot instead of filled dot).
- A specific percentile can be found by guesstimating the value on a cumulative frequency curve. - A specific percentile can be found by guesstimating the value on a cumulative frequency curve.