I think this is a simple question. I have a big table of data points and I want to take a an average of a subset of a single column. For example, if A is "age" and B is "gender," what command could I use to calculate the average age of women in my table?

I know I can do this by sorting the table by column B and then only selecting column A values, but I want to build up to much more complicated conditional terms (e.g. if A is 5 and B is 3 and C is 4, then give me the average of D).

Thanks!