What do you think about this one

Question

What do you think about this one?

Summer3 · Answer

Answer is E.

Both X and Z have mean = median = 40.

nick_sun · Answer

But how do we find mean in those graphs? :roll:

mavery · Answer

For x...
10*(1 block)+20*(2 blocks)+30*(3 blocks)+40*(4 blocks)+50*(3 blocks)+60*(2 blocks)+70*(1 block)=

10+40+90+160+150+120+70=640

Divided by 16 total blocks = mean of 40

z is done the same way...

Summer3 · Answer

Even if you just look at the graphs, X and Z show some symmetry. Mean is the centre point here.....so without adding up all the numbers just pinpoint the central block, which is 40 for both X and Z. Same with median here....
but Y does not show any symmetry.....so you can calculate mean and median here just to confirm if they are equal or not.

StartupAddict · Answer

I got X&Z.

I looked at the options first, there was none with 3, so I picked 2 to test, X&Z. 

First I did X by multiplying out the blocks in my head, Z was 760, divided by 19 in total, a mean of 40, and the median is 40 (as there are the same # of blocks on the left & right side).

Then I tested X quickly, same thing, 640/16=40, median is 40.

Answer = E - X&Z.

What do you think about this one

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