Ex 14.1, 8 - A class teacher has the absentee record of - Mean

  1. Chapter 14 Class 10 Statistics
  2. Serial order wise

Transcript

Ex 14.1, 8 A class teacher has the following absentee record of 40 students of a class for the whole term. Find the mean number of days a student was absent. Number of days Number of students 0 – 6 11 6 – 10 10 10 – 14 7 14 – 20 4 20 – 28 4 28 – 38 3 38 – 40 1 (0 + 6)/2=3 (6 + 10)/2=8 (10 + 14)/2=12 (14 + 20)/2=17 (20 + 28)/2=24 (28 + 38)/2=33 (38 + 40)/2=39 11 × 3=33 10 × 8=80 7 × 12=84 4 × 17=68 4 × 24=96 3 × 33=99 1 × 39=39 ∑▒𝑓𝑖𝑥𝑖= 499 We will do the question by direct method as class interval is not same Mean(𝑥 ̅) = (∑▒𝑓𝑖𝑥𝑖)/(∑▒𝑓𝑖) 𝑥 ̅ = 499/40 𝑥 ̅ = 12.48 Mean number of days a student was absent is 12.48

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Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 8 years. He provides courses for Maths and Science at Teachoo. You can check his NCERT Solutions from Class 6 to 12.