Medium MCQ +4 / -1 PYQ · JEE Mains 2022

If the mean deviation about median for the numbers 3, 5, 7, 2k, 12, 16, 21, 24, arranged in the ascending order, is 6 then the median is :

  1. A 11.5
  2. B 10.5
  3. C 12
  4. D 11 Correct answer

Solution

<p>Median $= {{2k + 12} \over 2} = k + 6$</p> <p>Mean deviation $= \sum {{{|{x_i} - M|} \over n} = 6}$</p> <p>$$ \Rightarrow {{(k + 3) + (k + 1) + (k - 1) + (6 - k) + (6 - k) + (10 - k) + (15 - k) + (18 - k)} \over 8}$$</p> <p>$\therefore$ ${{58 - 2k} \over 8} = 6$</p> <p>$k = 5$</p> <p>Median $= {{2 \times 5 + 12} \over 2} = 11$</p>

About this question

Subject: Mathematics · Chapter: Statistics · Topic: Measures of Central Tendency

This question is part of PrepWiser's free JEE Main question bank. 91 more solved questions on Statistics are available — start with the harder ones if your accuracy is >70%.

Drill 25 more like these. Every day. Free.

PrepWiser turns these solved questions into a daily practice loop. Chapter-wise drills, full mocks, AI doubt chat. No auto-renew.

Start free →