Link to what was previously discussed in Statistics (an **Elementary Math** **E-Math topic**) in Drawing & Understanding of Cumulative Frequency, here are the 5 features for a Box & Whisker Plot (I guess you would know which part represents the box, and the portion which are the whiskers)

- Minimum
- Lower Quartile, Q1
- Median
- Higher Quartile, Q3
- Maximum

Note the difference between these 2 terms:

**Range** = Max - Min

**Interquartile Range (IQR) **= Q3 - Q1

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[...] In my next post, I will be discussing the features of box and whisker plot. [...]

I think you've forgotten the outlier but i'm not sure if the singapore examination system covers them. E.g. if the exams marks for a class are 80+/- 10, and one person gets a say, 34 (unfortunately), a long line till 34 would misrepresent the data. Or to quote some website on the net:

"Sometimes there is ONE piece of data that falls well outside the range of the other values. This single piece of data is called an outlier. If the outlier is included in the whisker, readers may think that there are grades dispersed throughout the whole range from the first quartile to the outlier. "

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alwaysLovely Reply:

January 30th, 2009 at 2:19 pm

Hi Anon,

Thanks for the add on, it's not required to know about the concept of outlier in Singapore.

:)

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[...] E-Math: 5 Features of Box and Whisker Plot You Must Know [...]

how come Q1 for 8 numbers is the one btn 2 and 3... and Q1 for 9,10,11 numbers is the third one

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