Hey,
according to my knowledge, and I might be wrong, the question should be solved as illustrated below. however, I wanted to highlight this to either correct or assure myself
the Data Analysis question of finding the IQR = Q3-Q1 of the list (1,3,4,8,9,11,13) should be as follows:
Q2= 8
Q1= median of first half including Q2= (3+4)/2=3.5
Q3=meand of the second half including Q2 = (9+11)/2=10
IQR=10-3.5
kindly advice!
regards