Following are the marks obtained by 9 students in a Mathematics test 50, 69,20,33, 53, 39, 40,65,59 The mean deviation from the median is

Firstly, given marks are arranged in ascending order 20, 33, 39, 40, 50, 53, 59, 65, 69∴  Median, Md=9+12 th term =5 th term =50∴ Mean deviation, MD=∑i=19 xi−Mdn|20−50|+|33−50|+|39−50|+|40−50|+∣50=−50|+|53−50|+|59−50|+|65−50|+|69−50∣9=30+17+11+10+0+3+9+15+199=1149=12.67