Statistics
Measures of middle (mean, median and mode)

Statistics

Univariate statistics

• Measures of middle (mean, median mode)
• Measures of spread (range and interquartile range)
• Measures of spread (standard deviation)
• Histograms
• Box plots​

Bivariate statistics

• Association between variables
• The effect of outliers on correlation
• Causality
• Interpreting Pearson's correlation coefficient
• Interpolation and extrapolation​​

We can gain a better understanding of a data set by locating the middle or centre of the data and measuring the spread. Knowing one of these without the other is often of little use.
There are three statistics that can be used to measure the centre of a data set:
The mean: is commonly referred to as the average and is found by the sum of all data values divided by the total number of data values.
The median: is the middle value of an ordered data set.
​The mode: is the most frequently occurring value in the data set.