Had trouble with the list comprehension part.

Went ahead and did it with a loop. Couldn't get the different syntax to work using a list comprehension for avgAgeByGender.
The code is much simpler (and easier to read) when using list comprehensions. For example, the code in this case would be:
myAges = [int(row[2]) for row in myLists[1:]]

Think of a list comprehension as a for loop, where the inside of the for loop is at the front. So basically, this line says "for each row in myLists (starting with element 1 instead of element 0), take the second element of that row, make it an integer, and add it to the list".

The bottom of this page is a nice quick explanation of list comprehensions:
https://developers.google.com/edu/python/sorting