Examples

Chapter 13 Class 11 Statistics
Serial order wise

### Transcript

Example 3 Find the mean deviation about the median for the following data: 3, 9, 5, 3, 12, 10, 18, 4, 7, 19, 21. Arranging data in ascending order, 3, 3, 4, 5, 7, 9, 10, 12, 18, 19, 21 Here, number of observations = n = 11 (odd). Since n is odd, Median = ( 11 + 1﷮2﷯)th observation M = ( 12﷮2﷯)th observation = 6th observation = 9 Now, we calculate mean deviation about median 3, 3, 4, 5, 7, 9, 10, 12, 18, 19, 21 Median (M) = 9 Mean deviation about median = ﷮﷮ 𝑥𝑖 −M﷯﷯﷮11﷯ M.D.(M) = 3 − 9﷯ + 3 − 9﷯ + 4 − 9﷯ + 5 − 9 ﷯ + 7 − 9﷯ + 9 − 9﷯ ﷮+ 10 − 9﷯ + 12 − 9﷯+ 18 − 9﷯ + 19 − 9﷯ + 21 − 9﷯ ﷯﷯﷮11﷯ = −6﷯ + −6﷯ + −5﷯ + −4 ﷯ + −2﷯ + 0﷯ ﷮+ 1﷯ + 3﷯+ 9﷯ + 10﷯ + 12﷯ ﷯﷯﷮11﷯ = 6 + 6 + 5 + 4 + 2 + 0 + 1 + 3 + 9 + 10 + 12﷯﷮11﷯ = 58﷯﷮11﷯ = 5.27

#### Davneet Singh

Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 14 years. He provides courses for Maths, Science, Social Science, Physics, Chemistry, Computer Science at Teachoo.