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
Ai Ling Ong
Hi, I'm Ai Ling Ong. I enjoy coaching students who have challenges with understanding and scoring in 'O' Level A-Maths and E-Maths. I develop Math strategies, sometimes ridiculous ideas to help students in understanding abstract concepts the fast and memorable way. I write this blog to share with you the stuff I teach in my class, the common mistakes my students made, the 'way' to think, analyze... If you have found this blog post useful, please share it with your friends. I will really appreciate it! :)
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. "
Hi Anon,
Thanks for the add on, it's not required to know about the concept of outlier in Singapore.
:)
how come Q1 for 8 numbers is the one btn 2 and 3... and Q1 for 9,10,11 numbers is the third one