One will take the vector as an argument and return the average (as an integer) of the numbers in the vector.

Another will return the largest number in the vector and a third will return the smallest.

The last one will take the vector as an argument and using the one that calculates the average, return a count of the number of times the average value appears in the vector. Now, since the average is probably not an exact integer, you should count as matching any number that is 1 greater or 1 less than the average. So if the average is 13; 12,13,14 would match.

Lastly, you should have a function that prints the vector.
Remember, iterators only.