Mean of a List

The mean is the "add it all up and share it out evenly" average: total the values, then divide by how many there are.

Task: write mean(values) returning that average, rounded to 4 decimal places.

What you can count on:

• values is a list of numbers and is never empty, so you'll never divide by zero.
• The numbers can be whole or decimal, positive or negative. Order doesn't matter here — adding them up gives the same total either way.
• Return a single number, not a list.

Watch what the last test does to your answer: one value far from the rest pulls the mean toward itself, because every value gets an equal say in the total.