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Last updated at Sept. 24, 2018 by Teachoo

Transcript

Ex 14.3, 2 - Chapter 14 Class 10 Statistics - NCERT Book If the median of the distribution given below is 28.5, find the values of x and y. Since Median = 28.5 given So, 20 - 30 is the median class Class interval Frequency Cumulative frequency 0 β 10 5 5 10 β 20 x 5 + x 20 β 30 20 5 + x + 20 = 25 + x 30 β 40 15 25 + x + 15= 40 + x 40 β 50 y 40 + x + y 50 β 60 5 40 + x + y + 5= 45 + x + y Totalββππ =60 Median = l + (π/2 βππ)/π Γ h Where l = lower limit of median class=20 h = class-interval= 10 β 0 = 10 n = ββππ=60 π/2=60/2 = 30 cf = cumulative frequency of the class before median class= 5 + x f = frequency of the median class=20 Median = l + (π/2 βππ)/π Γ h 28.5 = 20 + (30 β (5+ π₯))/20 Γ 10 28.5 = 20 + (25 β π₯)/2 28.5 β 20 = (25 β π₯)/2 8.5 = (25 βπ₯)/2 8.5 Γ 2 = 25 β x 17 = 25 β x x = 25 β 17 x = 8 Also, ββππ = 5 + x + 20 + 15 + y + 5 60 = 45 + x + y 60 = 45 + 8 + y 60 = 53 + y 60 β 53 = y 7 = y y = 7 Hence, x = 8, y = 7

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Davneet Singh

Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 9 years. He provides courses for Maths and Science at Teachoo.