The average is 13.
sorted: 1 2 7 9 11 15 19 20 number of items: 8 middle items: 9 and 11 average of middle items, or median: (9+11)/2 = 10
Add them together and divide by 6.
It is: 13+9+11 = 33 and 33/3 = 11 which is the mean average
The average is 19.
there were 19 hijackers involved in 9/11 and they hijacked 4 planes ......
Average: (13+9)/2 = 11
11+9=20 20/2=10 average:10
Average = (6+9+10+11)/4 = 36/4 = 9
The approximate average is 19. The actual average is 19 and 1/3
15
the average of 7,9,11,12,16 is = (7+9+11+12+16)/5 =11
The average is 10... 11+11+9+7+12=50... 50/5=10