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.
Variance. In probability theory and statistics, the variance is a measure of how far a set of numbers is spread out. It is one of several descriptors of a probability distribution, describing how far the numbers lie from the mean. In particular, the variance is one of the moments of a distribution. In that context, it forms part of a systematic approach to distinguishing between probability distributions.