Central tendency involves the idea that there’s one figure that’s in a way
central to the whole set of figures. Measures of central tendency include the
mean, the median, and the mode. They summarize a whole lot of figures
with one single number. This will obviously make it easier for people to
understand and use the data.
The mean is the average of all the figures. In other words, the sum of them
all divided by how many there are. If the distribution of measurements is
random, the mean represents the value that’s expected.
The median is the figure in the middle once all the figures have been put
into numerical order. In other words, half of the numbers we have will be
smaller than this median number, and half will be bigger.
The mode is the figure that occurs most often. It’s the most frequently
appearing number in the number set.
Dispersion refers to how spread out the figures are from a central number.