Propagation of Asymmetric Errors

I am working on a problem that requires me to divide radiated mass by peak strain, both of which have asymmetric errors. I do not know the details of the error profiles. What techniques are used for the propagation of errors? Basically, I want to compute something like
I appreciate your help. Thanks.

You may have found an answer to your question by now. If not, here is an informative and fairly complete discussion on the Stackexchange forum on astronomy:

Hope this helps!