Answer :
Mean: add A1+A2+A3+A4+……..+An then divide by 2 means 8+5+7+10+15+21=66/2=33
D. 11
you add all of the number then divide by how many numbers there are.
8+5+7+10+15+21= 66
there are 6 numbers total
66/6=11
you add all of the number then divide by how many numbers there are.
8+5+7+10+15+21= 66
there are 6 numbers total
66/6=11