PMP Exam Simulator

While overseeing the project on the fish reservoir construction, the project manager tried to find out the root cause of a critical problem in the production process. Two variables have been identified by the team as the conceivable contributors to the problem. These are humidity and temperature. The project manager is worried that temperature and humidity are complicating the problem by affecting each other. Which tools and techniques will be useful to find out whether there is any interdependency between two variables?