First, you'd find the mean of all the numbers by doing 10+9+16+5+10 = 50/5 = 10. Second, you'd subtract all values from the mean by doing
16 - 10 = 6
10 - 10 = 0
10 - 10 = 0
10 - 9 = 1
10 - 5 = 5
Lastly, finding the mean of all 5 numbers would be, 2.4! Hope this helps!! :D