Franklin D. Roosevelt: Life Before the Presidency. Franklin D. Roosevelt: Life Before the Presidency. Franklin Delano Roosevelt was born to James and Sara Roosevelt in 1882. James was a land-owner and businessmen of considerable, but not awesome, wealth from New York.
How to Measure Variability in Statistics. Statisticians use summary measures to describe the amount of variability or spread in a set of data. The most common measures of variability are the range, the interquartile range (IQR), variance, and standard deviation.
In statistics, the coefficient of determination R2 is the proportion of variability in a data set that is accounted for by a statistical model. In this definition, the term variability is defined as the sum of squares. There are equivalent expressions for R2 based on an analysis of variance decomposition.