Azoo measured the wingspan, in millimeters, of 9 butterflies.
55 50 54 57 50 55 53 52 55
what is the median length of the wingspans?
50 mm
54 mm
55 mm
57 mm

Median means Average,
and  the Average = sum of all the number ÷ number of points
So, the medium here =
50 + 50 + 52 + 53 + 54 + 55 + 55 + 55 + 57 ÷ 9

Therefore, the median is 54mm.

I hope this cleared your confusion! ;)

Graph a should be your answer