Answer:
range=14
mode=9
median =9
mean =12
Step-by-step explanation:
range is B-S=20-6
mode is most common
median put in order find middle value 6,9,9,9,9,11,13,16,18,20
mean is add all divide by how many 9+9+9+9+6+11+13+16=120/10
If i get one wrong i am sorry
