Published on Texas Gateway (https://texasgateway.org)
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 ∑ ​ ​ x 2 − [ ∑ ​ ​ x] 2 )(n ∑ ​ ​ y 2 − [ ∑ ​ ​ y] 2 ) r= n ∑ ​ ​ xy−[ ∑ ​ ​ x][ ∑ ​ ​ y] (n ∑ ​ ​ x 2 − [ ∑ ​ ​ x] 2 )(n ∑ ​ ​ y 2 − [ ∑ ​ ​ 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