1.4 Types of data

Quantitative variables / Quantitative data

Variables or data associated with numerical observations

e.g. shoe size (number)

Qualitative variables / Qualitative data

Variables or data associated with non numerical observations

e.g. Hair colour

Continuous variables

A variable that can take any value in a given range

e.g. time can be 2 seconds, 2.1 seconds, 2.01 seconds

Discrete variables

A variables that can take only specific values in a given range

e.g. Age - must be integer. Or number of boys in a classrom - must be integer

what is midpoint and class width in a grouped frequency table

the average of the class boundaries.

the difference between the upper and lower class boundaries