i)The number of insect in country X is 71(10+18+16+16+11)
So the median is (n+1)/2(since 71 is an odd number) term i.e. ((71+1)/2)=36th term,which is 0.825cm
lower quartile is (71/4)=18th term(0.814cm),upper quartile=71*(3/4)=54th term(0.833cm)
inter-quartile range=upper quartile-lower quartile=0.833-0.814=0.019
ii)lower quartile of country Y=(83/4)=21th term(0.82qcm),upper quartile=63th term(0.85rcm)
inter-quartile range=upper quartile-lower quartile
0.028=0.85r-0.82q
since in stem-and-leaf diagram r is between 2&3 so it must be 2 or 3 and since q is between 3&4 so it must be 3 or 4 .At the same time the difference between upper quartile & lower quartile must be 0.028cm,so when r=2 & q=4,all the above condition matches.
