Line 79 of exercises/concept/card-games/.docs/instructions.md appears to have an error. Perhaps it was a typo but 4 is not the average of the list, nor the average of the first and last, while 5 is. So either the middle item should be 5 or the result should be False.
There are two approximate averages you need to check against the actual average (5). One (the middle value) is 4. The other (average of the first and last) is 5. Therefore one of the approximate average values is equal to the actual average.
