Square Root Day September 9, 1981 (9/9/81). Gordon remains the holiday's publicist, sending news releases to world media outlets. Gordon's daughter set up a Facebook group where people can share how they were celebrating the day. One suggested way of celebrating the holiday is by eating square radishes, or other root vegetables cut into shapes with square cross sections (thus creating a "square root"). Square Root Day occurs on the following dates each century: The number of years between consecutive Square Root Days in a century are consecutive odd numbers: 3, 5, 7, 9, 11, 13, 15, 17. This illustrates the fact that
Root-mean-square deviation square root of the average of squared errors. The effect of each error on RMSD is proportional to the size of the squared error; thus larger errors have a disproportionately large effect on RMSD. Consequently, RMSD is sensitive to outliers. The RMSD of an estimator formula_1 with respect to an estimated parameter formula_2 is defined as the square root of the mean square error: For an unbiased estimator, the RMSD is the square root of the variance, known as the standard deviation. The RMSD of predicted values formula_4 for times "t" of a regression's dependent variable formula_5 with variables observed