College students (n = 83) were observed during their final exams. The amount of time taken to complete the exam was recorded, and correlated with the grade (r = -.13, p = .22).   What should we conclude?

Correlation in statistics is a measure of the relationship between two variables. It is used to determine if a change in one variable is associated with a change in another variable. A correlation can be either positive or negative, indicating that the two variables are either positively or negatively related. 

The most commonly used measure of correlation is Pearson's correlation coefficient, which ranges from -1 to 1. A positive correlation means that as the value of one variable increases, the value of the other variable also increases. A negative correlation means that as the value of one variable increases, the value of the other variable decreases. A correlation of 0 indicates that there is no relationship between the two variables.

In conclusion, correlation is a useful tool in statistics that helps us understand the relationship between two variables. By measuring the strength and direction of the relationship, we can gain insights into the underlying factors that influence behavior and outcomes.