Answer:
what is mean: mean is the "average" of a set of numbers and it is calculated by adding up the values given and dividing by the total number of values given.
Explanation:
formula: addition of all values divided by the number of values given.
total number of values given = 10 ( count each number as one )
so ..
20+15+22+13+14+18+19+11+23+17 = 172
divided by 10
= 17.2 ( decimal)
or 17 whole number 1/5 ( mixed fraction )
or 86/5 ( improper fraction ).
Hope this helps.
Good luck .