Define these key terms

1. Latent variable: a variable that we didn’t measure but infer from our data
2. Mean: the average value, calculated as the sum of the values divided by n
3. Standard deviation: the spread of values, calculated as the square root of the sum of the squared deviations divided by n

Fill in the gaps

1. The median is the middle value in an ordinal data set
2. The inter-quartile range can be used to measure dispersion in an ordinal. variable.
3. The measure of central tendency for a categorical variable is the mode.

Identify the variable type for each of the variables

 Variable Method Type of Measurement? Interval/Categorical/Ordinal Happiness Self-rated report using a Likert scale Ordinal Dog Organised by breed Categorical Height Scale in centimetres Interval Weather Mm of rainfall Interval Caffeine status Measurements taken before and after drinking coffee Categorical Social media Hours spent on social media Interval Pain Self-rated using a low-high set of options Ordinal Top level of education Categorising from primary school through to postgraduate Ordinal