# Chapter 6 | Question 1

You want to investigate the correlation between variables X and Y. The relationship is monotonic but non-linear. Which correlation coefficient will you use?

Pearson’s *r* or Kendall’s *τ*

Pearson’s *r* or Spearman’s *ρ*

Spearman’s *ρ* or Kendall’s *τ*

none of the above