Page 1 - Lesson Note MCT 2 52

SAI INTERNATIONAL SCHOOL

ECONOMICS

Class-XI

CHAPTER 9

Measures of Central Tendency – Median and Mode

(Lesson Note - 52)

TOPICS TO BE COVERED-

-Meaning of Median.

-Steps to calculate median in individual, discrete and continuous series.

-Problems on individual, discrete and continuous series.

Median: -

Median may be defined as the middle value in the data set when its
elements are arranged in a sequential order, that is, in either as
ascending or descending order of magnitude.

50% of data ≤ Median ≤ 50% of data.

Steps to calculate Median in case of Individua series: -

 First arrange the data either in ascending or descending order.
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 Median (Me) = Size of ( )th item. Where, n:- no of data.
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Odd and Even Number of items:
(i) In case of odd numberitems Median = Middle item of distribution.
(ii) In case of Even number of items: Median = Average of two

middleterms.

Ex: Marks of five students are 42, 40, 60, 55 and 50 calculate median.

Step 1: Marks arranged in ascending order 40, 42, 50, 55, 60.
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Step 2: Me = size of [ ]th item.
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