Answer:
A
Explanation:
Remark
An average is found by adding all the members of a group, and then dividing by the number in the group.
Solution
Sum = 1 + 9 + 11 + 13 + 26
Sum = 60
Number in the group 5
Average and answer
Average = Sum / number in the group
Average = 60/5 = 12
Answer 12