Misc 6 - Mean, standard deviation of marks obtained by 50 - Co-efficient of variation


  1. Chapter 15 Class 11 Statistics
  2. Serial order wise
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Misc 6 The mean and standard deviation of marks obtained by 50 students of a class in three subjects, Mathematics, Physics and Chemistry are given below: Which of the three subjects shows the highest variability in marks and which shows the lowest? To compare the variation, we have to calculate coefficient of variation Coefficient of variation(C.V.) = ๐‘บ๐’•๐’‚๐’๐’…๐’‚๐’“๐’… ๐‘ซ๐’†๐’—๐’Š๐’‚๐’•๐’Š๐’๐’๏ทฎ๐‘ด๐’†๐’‚๐’๏ทฏ ร— 100 For Chemistry Mean = 40.9 Standard deviation = 20 CV = ๐‘†๐‘ก๐‘Ž๐‘›๐‘‘๐‘Ž๐‘Ÿ๐‘‘ ๐‘‘๐‘’๐‘ฃ๐‘–๐‘Ž๐‘ก๐‘–๐‘œ๐‘›๏ทฎ๐‘€๐‘’๐‘Ž๐‘›๏ทฏ ร— 100 = 20๏ทฎ40.9๏ทฏ ร— 100 = 48.89 So, CVmaths = 28.57, CVphysics = 46.87, Cvchemistry = 48.89 Since chemistry has highest CV, it has highest variability & Mathematics has lowest CV, so it has lowest variability.

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