Answer:

Step-by-step explanation:





Arrange in ascending order:-
6 7 11 13 14 15 15 19 21
median = 14
lower quartile = mean of 7 and 11 = 9
upper quatile = mean of 15 and 19 = 17
Interquartile range = 17 - 9 = 8
answer is 8
The third and fourth charts represent functions