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Fayetteville State Univ.: Variance & Standard Deviation
Quick definitions of these statistical terms are provided, then followed by an example covering both of them. This page is part of a larger series which gives simple explanations of common, useful statistical concepts.
University of Illinois
University of Illinois: Keep Off the Median
Resource contains a problem involving a group of test scores. Students are instructed to find the median or middle score. There links to other sites also listed on this one.