You must know how to calculate the standard deviation from given summary data using the formula: \displaystyle \sqrt{\frac{\sum x^2}{n} - \bar{x}^2}

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## Glossary

### standard deviation

The square root of the variance; a measure of dispersion.

### union

The union of two sets A and B is the set containing all the elements of A and B.

**Full Glossary List**

More in this topic

1 Variance

2 Standard deviation

3 Calculate standard deviation

4 Calculate standard deviation 2

5 Calculate standard deviation 3

6 Interquartile range

7 Skewness

8 Standard deviation on a GDC

9 Standard deviation on a GDC 2

10 Interquartile range on a GDC

11 Summary stats on a GDC

12 Skewness O-test

13 Timed O-test

14 Exam O-test 1

15 Exam O-test 2

16 Exam timed O-test

17 Exam Question 2000

18 Exam Question 2002

19 Exam Question 2006

20 Exam Question 2008

21 Exam Question 2008

22 Exam Question 2008

23 Exam Question 2008

24 Exam Question 2008

25 Exam Question 2008

26 Exam Question 2010

27 Exam Question 2011

28 Exam Question 2014