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 Calculate standard deviation

2 Variance

3 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

18 Exam Question

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