## Key Terms

coefficient of correlation
a measure developed by Karl Pearson during the early 1900s that gives the strength of association between the independent variable and the dependent variable;
$r=n∑​​xy−[∑​​x][∑​​y](n∑​​x2−[∑​​x]2)(n∑​​y2−[∑​​y]2)r=n∑​​xy−[∑​​x][∑​​y](n∑​​x2−[∑​​x]2)(n∑​​y2−[∑​​y]2)$
where n is the number of data points

The coefficient cannot be more than 1 and less than –1. The closer the coefficient is to ±1, the stronger the evidence of a significant linear relationship between x and y.
outlier
an observation that does not fit the rest of the data