An internal auditor wants to examine the intensity of correlation between electricity price and wind...

A scatter diagram plots two variables on a graph to examine whether there is a correlation or relationship. Here, electricity price and wind speed can be plotted to test if changes in one relate to changes in the other.

A Gantt chart (A) is for project scheduling.

A RACI chart (C) clarifies roles and responsibilities.

A SIPOC diagram (D) maps processes.

Therefore, the best analytical tool for correlation analysis is the scatter diagram.