Answer:
Median= 6.5
lower quartile=4
upper quartile=9
Step-by-step explanation:
Order first: 1,2,4,5,6,7,8,9,10,11
Median= 6+7=13 and 13/2=6.5 (the middle number of the entire set, if two are in the middle then add both of the number and divide by 2)
lower quartile= 1,2,4,5,6... 4 (middle number of first half)
upper quartile=7,8,9,10,11...9 (middle number of second half)