Answer:
12.
Step-by-step explanation:
To find the mean of a group of data, you add up all of the numbers and divide the total by the amount of numbers there are. In this case, you have 15,11,10,11,14,10,15,10,and 12.
All of those numbers added together is 108.
108 divided by 9 numbers, or weeks, is 12.
The average, or mean, is 12.