What does a larger standard deviation indicate?
It shifts every value equally.
For grouped data, the variance formula is s2=∑fx2∑f−xˉ2s^2=\frac{\sum fx^2}{\sum f}-\bar{x}^2s2=∑f∑fx2−xˉ2.
The efficient raw-data variance formula is s2=∑x2n−xˉ2s^2=\frac{\sum x^2}{n}-\bar{x}^2s2=n∑x2−xˉ2.
The data are more spread out.
Flashcards for Edexcel A Level Maths 2.4 Variance and Standard Deviation, covering the key formulae, methods and definitions you need to recall for Paper 1, Paper 2 and Paper 3. 20 cards, matched to the Edexcel A Level Maths (9MA0) specification. Recall questions account for roughly 50% of marks at A Level Maths, so these target the marks you can secure before the paper starts.
