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Sampling and More Complex diagrams
- Frequency Density = Frequency ÷ Class Width
- Frequency = Frequency Density x Class width
Histograms
- There is continuous data (no gaps between classes).
- When each class width/interval is not equal.
- The area (l x b) represents the frequency, not height.
![broken image](http://custom-images.strikinglycdn.com/res/hrscywv4p/image/upload/c_limit,fl_lossy,h_9000,w_1200,f_auto,q_auto/4936730/617272_737591.png)
When it comes to IGCSE/GCSE Maths, do you remember how to interpret box plots?
Box Plots
- When data is ordered:
- LQ = 1/4(n+1)
- Median = ½ (n+1)
- UQ = 3/4(n+1)
- Interquartile range = UQ - LQ
- Positive skew = when median is closer to LQ than UQ
- Negative skew = when median is closer to UQ than LQ
- Symmetrical distribution = even spread from LQ to UQ
- Outlier = does not fit the trend, or more than 1.5x the interquartile range below LQ/above UQ
![broken image](http://custom-images.strikinglycdn.com/res/hrscywv4p/image/upload/c_limit,fl_lossy,h_9000,w_1200,f_auto,q_auto/4936730/570255_463275.png)
That's the end of the topic!
![broken image](http://custom-images.strikinglycdn.com/res/hrscywv4p/image/upload/c_limit,fl_lossy,h_9000,w_1200,f_auto,q_auto/4936730/65795_55816.png)
Drafted by Bonnie (Mathematics)