Stochastic Processes in Chemical Engineering? Secondary major?

It depends on what you want to do with your career.

Do you plan to stick around the university for an advanced ChemE degree? Are you planning on going into research or do some advanced modeling? Do you prefer a job that is more science oriented? If so then I would take this class.

Personally, I pursued a mathematics minor and chemistry minor because I wanted to branch out more in the foundation sciences. Personally, I preferred the math taught by the Chem E department. I wasted less time on learning theory that I never directly applied.

I went into industry and have not applied the advanced math skills yet. If I were to do it again I would have taken more course offered by the department. The professors better understood the applications and were able to teach to that direction.

Sometimes the brain can find more creativity when branching together classes from different departments, but it just didn't work that way for me.