Answer:
-1
Step-by-step explanation:
The mean is the sum of all values divided by the amount of values.
We take the sum of all the numbers:
-3 + -8 + 12 + -15 + 9
-11 + 12 + -15 + 9
1 + -15 + 9
10 + -15
-5
We then divide the sum by how many number we have (we are given 5 numbers):
-5/5 = -1
Therefore, our mean is equal to -1.
