# Ex 14.2, 4 - Chapter 14 Class 10 Statistics

Last updated at Sept. 25, 2018 by Teachoo

Last updated at Sept. 25, 2018 by Teachoo

Transcript

Ex 14.2, 4 The following distribution gives the state-wise teacher-student ratio in higher secondary schools of India. Find the mode and mean of this data. Interpret the two measures. Mode = l + (๐1 โ๐0)/(2๐1 โ๐0 โ๐2) ร h Modal class = Interval with highest frequency = 30 โ 35 where l = lower limit of modal class h = class-interval f1 = frequency of the modal class f0 = frequency of class before modal class f2 = frequency of class after modal class Mode = l + (๐1 โ๐0)/(2๐1 โ๐0 โ๐2) ร h = 30 + (10 โ9)/(2(10) โ 9 โ 3) ร 5 = 30 + 1/(20 โ12) ร 5 = 30 + 5/8 = 30 + 0.625 = 30.625 Number of students / teacher Number of States/ U.T. 15 โ 20 3 20 โ 25 8 25 โ 30 9 30 โ 35 10 35 โ 40 3 40 โ 45 0 45 โ 50 0 50 โ 55 2 Mean(๐ฅ ฬ ) = a + h ร (โโ๐๐๐ข๐)/(โโ๐๐) Where a = assumed mean h = Class interval = 20 โ 15 = 5 & ui = (๐ฅ๐ โ๐)/โ โโ๐๐ = 35 โโ๐๐๐ข๐ = -58 Mean(๐ฅ ฬ ) = a + h ร (โโ๐๐๐ข๐)/(โโ๐๐) Mean(๐ฅ ฬ ) = 37.5 + 5 ร (โ58)/35 Mean(๐ฅ ฬ ) = 37.5 - 58/7 ๐ฅ ฬ = 37.5 โ 8.286 ๐ฅ ฬ = 29.214 โด Mean = ๐ฅ ฬ = 29.214 Thus, most states have student-teacher ratio 30.625 (mode), And average student-teacher ratio is 29.214 (mean)

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