Subject: Mathematics
Book: Maths Mastery
Variance measures how spread out data values are around the mean, calculated by averaging the squared differences from the mean. Standard deviation is the square root of variance, returning the measure to the original data units. For a dataset [2, 4, 4, 6, 8], the mean is 4.8, each difference is (2 – 4.8)², (4 – 4.8)², etc., then averaged to get variance, and the square root yields the standard deviation. Higher standard deviation indicates greater spread. These metrics are fundamental in statistics, quality control, finance risk, and any field requiring data analysis. Familiarity with variance and standard deviation fosters statistical literacy and well-informed decisions.
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