Do such questions appear regularly?This blew me out. Any simple way?
You can, for example never foretell what any one man will do, but you can say with precision what an average number will be up to!
As we can see the frequency distribution chart for X 10 appears one time, 20 appears 2 times and so on till 70 appear one time,
mean = [10+20+20+30+30+30+40+40+40+40+50+50+50+60+60+70]/16
we get 40, and here we can see in normal distribution median is also 40
so mean = median for X's distribution
using same calculation we"ll find mean = median for Z's distribution which is 40
Ans is E, we dont need to check for Y
In order to avoid calculation for Z, for quick visualize approach we can see graph is symmetrical around 40
