Answer:
8
Step-by-step explanation:
To find the mean, or average of a data set, add all the values together, then divide by the number of values.
The data set is: 6,7,9,9,9
1. Add all the values
Add 6,7,9,9 and 9
6+7+9+9+9
40
2. Divide by the number of values
Count how many numbers are in the data set. In this case, there are 5 numbers.
Divide 40 by 5.
40/5
8
The mean of the data set is 8.