Advice: Linear Regression and Rank Correlation
Interval (normal) vs. Interval (non-normal)
SIMPLE LINEAR REGRESSION AND RANK CORRELATION: Regression can be found in the regression and correlation section and rank correlation is listed under nonparametric methods. You are advised to use Kendall's rank correlation as this reflects the strength of the relationship between the variables and copes with ties much better than Spearman's method. For the regression the residuals about the fitted line must be from a normal distribution and display uniform variance.