are there any rules/facts any of you have come up with for SD, median and average...that GMAT tends to ask frequently?

like if the average is greater than the median, is the SD the same as the median? i know that question doesnt make sense, but stuff like that...where you really have to know how the 3 values are related to each other in different groups of numbers--consecutive, repeated numbers etc.

just wondering if any of you have made a list or something...

Don't have a list, no, but I think it's a great idea! Let's use this thread for people to post ideas.

Some tips to get us started:

Median and average questions are far more common than SD questions.
Most common will have to do with what we can tell about median and average when given consecutive integers. Play around with that concept and see if you can start us off with some rules there!