In statistics, bivariate data means two variables or measurements per observation. For purposes of this section, we will assume both measurements are numeric data. These variables are usually represented by the letters X and Y.
Example: Sunglasses sales and rainfall
A company selling sunglasses determined the units per 1000 people and the annual rainfall in 5 cities.
X = rainfall in inches
Y = sales of sunglasses per 1000 people.
In this example there are two numeric measurements for each of the five cities.