Sample Statistics

# The Sample Correlation

## The Problem

Pearson’s sample correlation is a measure of the relationship between two numeric variables. It is used to summarize the bivariate relationship. To illustrate the calculations, let us use the following example.

A professor would like to investigate the relationship between student score on the midterm and the final exam. To do this, the professor collected the exam scores from n = 5 students. Using the data below, what is that correlation?

Here is the data. Note that there are two measurements on each unit (student). We are interested in the relationship between those two measurements.

Table of the bivariate data generated
StudentMidtermFinal
IdentifierScoreScore
15879
28978
33828
43164
59582

Calculate the correlation of this sample.