Q.

If the mean deviation about the median of the numbers k, 2k, 3k, ....., 1000k is 500, then k² is equal to :     [2026]

1 9  
2 4  
3 1  
4 16  

Ans.

(2)

∵  median =1001k2=XM

∴  mean deviation about median =∑|Xi-XM|n

=2(k2+3k2+5k2+⋯ 500 terms)1000

=2·k2(500)21000

=500k2=500  (given)

∴ k=2

∴ k2=4