Mean and Standard Deviation of Ungrouped Data

Standard deviation

• Used to describe the distribution of data.

• The bigger spread of data, the higher the deviation.

Ungrouped Data:

\(\bar{x} = \frac{\sum x}{n}\)

Grouped Data:

\(\frac{\sum fx}{\sum f}\)

Formula to find standard deviation

\(\sqrt{\frac{\sum x^2}{n} - \bar{x}^2} \quad \text{or} \quad \sqrt{\frac{\sum(x - \bar{x})^2}{n}}\)