To answer your question about how many plays in a specific list were edited by Kenneth Muir, I would need to know which list you are referring to. Kenneth Muir was a notable scholar and editor of Shakespeare's works, and he edited several plays throughout his career.

If you can provide the specific list of plays or the context in which you are asking, I can give you a more precise answer. Alternatively, if you are looking for a general overview of Kenneth Muir's editorial work, I can provide that as well.