Maths Class 11 Chapter 15. Statistics | Page 3

Central Tendency It is a measure that tells us where the middle of a bunch of data lies .
3 most common measures of central tendency are the mean , the median , and the mode .
Let ’ s take a situation where Mary & Hari got marks for 5 questions . Both of them claim to have performed better . Let ’ s see who has performed better in the exam .
Mean : Let ’ s find the average scores . Average Score of Mary is ( 10 + 8 + 9 + 8 + 7 )/ 5 = 8.4 Average Score of Hari is ( 4 + 7 + 10 + 10 + 10 )/ 5 = 8.2 Based on the Mean data , Mary has performed better .
The mean ( or average ) of a number of observations is the sum of the values of all the observations divided by the total number of observations . It is denoted by ‘ x bar ’.