That's not how averages work. If you have four apples that are 1 month old each, and one apple that is 66 months old, the average age is 14 months, but a randomly chosen apple is 4 times more likely to be less than 14 months old than to be older.
That's exactly how averages work if you're using the median value rather than the arithmetic mean. If the median age for an apple is 14 months, then you have the same chance of selecting an apple that is either older or younger than 14 months.
"average" is generally taken to mean "arithmetic mean" when its meaning is not otherwise specified.