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Find the Mean, Variance and Standard Deviation Using Short-cut Method Height in Cms and No. of Children - CBSE (Arts) Class 11 - Mathematics

ConceptVariance and Standard Deviation Shortcut Method to Find Variance and Standard Deviation

Question

Find the mean, variance and standard deviation using short-cut method

 Height in cms No. of children 70-75 3 75-80 4 80-85 7 85-90 7 90-95 15 95-100 9 100-105 6 105-110 6 110-115 3

Solution

 Class Interval Frequency fi Mid-point xi y_i = (X_i - 92.5)/5 yi2 fiyi fiyi2 70-75 3 72.5 –4 16 –12 48 75-80 4 77.5 –3 9 –12 36 80-85 7 82.5 –2 4 –14 28 85-90 7 87.5 –1 1 –7 7 90-95 15 92.5 0 0 0 0 95-100 9 97.5 1 1 9 9 100-105 6 102.5 2 4 12 24 105-110 6 107.5 3 9 18 54 110-115 3 112.5 4 16 12 48 60 6 254

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Solution Find the Mean, Variance and Standard Deviation Using Short-cut Method Height in Cms and No. of Children Concept: Variance and Standard Deviation - Shortcut Method to Find Variance and Standard Deviation.
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