Data Analysis - TeachSG

🦉 Mode

Mode is the most frequently occurring number. A set of data can have more than one mode.

🦉 Mean

\text{mean} = \frac{\text{sum of all numbers}}{\text{number of numbers}}

🦉 Median

Median is the centre number when the numbers are arranged from smallest to largest.

🦉 Range

\text{Range} = \text{maximum} - \text{minimum}

🦉 Quartiles & Percentiles

0th percentile: minimum

25th percentile: lower quartile

50th percentile: median

75th percentile: upper quartile

100th percentile: maximum

🦉 Interquartile Range

\text{Interquartile range} = \text{upper quartile} - \text{lower quartile}

🦉 Mean & Standard Deviation

Ungrouped

\text{Mean}, \bar{x} = \frac{\sum x}{N}

\text{Standard deviation}, \sigma = \sqrt{\frac{\sum(x-\bar{x})^2}{N}}

Grouped

\text{Mean}, \bar{x} = \frac{\sum fx}{\sum f}

\text{Standard deviation}, \sigma = \sqrt{\frac{\sum fx^2}{\sum f} - \left(\frac{\sum fx}{\sum f}\right)^2}