To find the mean of these numbers, you need to add them all together and then divide by the total number of numbers.
Adding the numbers: 173 + 279 + 636 + 357 + 384 + 320 + 288 + 420 + 401 + 389 = 3,447
Total number of numbers: 10
Mean: 3447 / 10 = 344.7
Now let's put the numbers in order from least to greatest:
173, 279, 288, 320, 357, 384, 389, 401, 420, 636