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For six numbers, Σ x = 30 and Σ x² = 240. Using the… | StemPy Lab

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For six numbers, Σ x = 30 and Σ x² = 240. Using the shortcut formula for the group, what is the variance?

MathematicsMediumHigh School (11–12)Statistics and Probability › Statistics AP A-Level IB AEEE (Amrita)AMUEEE AP EAPCET

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For six numbers, $\sum x = 30$ and $\sum x^2 = 240$ . Using the shortcut formula for the group, what is the variance?

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← A student finds the standard deviation of the numbers 1, 3, 5. The mean is 3, the squared deviations are 4, 0, 4, their sum is 8, and she divides by 3 to get 8/3. She writes that the standard deviation is 8/3. Where is her mistake?A park ranger groups the lengths of 40 fallen branches, in classes of width 10 centimetres: 0 to 10 with frequency 3, 10 to 20 with 9, 20 to 30 with 14, 30 to 40 with 10 and 40 to 50 with 4. What is the median length, to two decimal places? →

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