Check sibling questions

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

Ex 14.1, 8 - Chapter 14 Class 10 Statistics - Part 2
Ex 14.1, 8 - Chapter 14 Class 10 Statistics - Part 3

This video is only available for Teachoo black users

Ex 14.1, 8 - Chapter 14 Class 10 Statistics - Part 4

Ex 14.1, 8 - Chapter 14 Class 10 Statistics - Part 5
Ex 14.1, 8 - Chapter 14 Class 10 Statistics - Part 6

This video is only available for Teachoo black users

Solve all your doubts with Teachoo Black (new monthly pack available now!)


Transcript

Ex 14.1, 8 (Method 1 – Direct Method) 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. Here Class Size is not same, So, we solve by Direct Method Putting values in formula Mean(π‘₯ Μ…) = (βˆ‘β–’π‘“π‘–π‘₯𝑖)/(βˆ‘β–’π‘“π‘–) π‘₯ Μ… = 499/40 𝒙 Μ… = 12.48 Therefore, Mean number of days a student was absent is 12.48 daysEx 14.1, 8 (Method 2 – Step Deviation Method) 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. Here Class Size is not same… So, in Step Deviation Method Mean(π‘₯ Μ…) = a + h Γ— (βˆ‘β–’π’‡π’Šπ’–π’Š)/(βˆ‘β–’π’‡π’Š) We use a value of h which can divide 𝑑𝑖 = π‘₯𝑖 βˆ’ a Mean(π‘₯ Μ…) = a + h Γ— (βˆ‘β–’π’‡π’Šπ’–π’Š)/(βˆ‘β–’π’‡π’Š) Where a = Assumed Mean Let h = Class interval Also, βˆ‘β–’π’‡π’Š = 40 βˆ‘β–’π’‡π’Šπ’–π’Š = βˆ’90.5 Putting values in formula Mean(𝒙 Μ…) = a + h Γ— (βˆ‘β–’π’‡π’Šπ’–π’Š)/(βˆ‘β–’π’‡π’Š) π‘₯ Μ… = 17 + 2 Γ— (βˆ’90.5)/40 π‘₯ Μ… = 17 – 4.525 𝒙 Μ… = 12.475 Therefore, Mean number of days a student was absent is 12.48 days

Davneet Singh's photo - Co-founder, Teachoo

Made by

Davneet Singh

Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 12 years. He provides courses for Maths, Science, Social Science, Physics, Chemistry, Computer Science at Teachoo.