Statistics

Some statistics :)

Categorical data

Data that doesn't require numbers, eg. Which ice cream flavour is your favourite.

Ordered data

Sub category of categorical data that requires an answer from a set of answers eg. What year are you in.

Unordered data

Sub category of categorical data that doesn’t require a specific answer eg. What's your favourite colour.

Numerical data

Data comprised of numbers eg. What age are you.

Discrete data

Numerical data that can only take certain values, eg. any question starting with "How many".

Continuous data

Numerical data that can take any value, ie. anything you measure, such as height, weight, etc.

The Mean

The sum of numbers over the amount of numbers.

The Median

The middle number in a ranked set of data. Formula: (n+1)÷2= number to count to to find the median.

The Mode

The most common data frequency.

Outlier

A statistic that is far away from the others, eg. counting the teacher's age when trying to find the average age of a class.

The Range

Highest statistic minus the lowest statistic.

Histograms

Like a bar chart except there are no gaps between the bars. Best for continuous data.

Stem and leaf plot

Displays numerical data.

Pie charts

A circular chart presenting data as sectors of the circle. The bigger the angle in a sector, the more frequent that data is.

Frequency tables

A chart that shows the classes of data and the amount of each class. Can be grouped, eg 10-20.

Mean of grouped frequency tables

When finding the mean of grouped frequency tables and finding the sum of the numbers, find the mid-interval value of each class. Multiply the mid interval values of each class by the amount in each class. Add up the totals and put them over the amount of the numbers.