Market Reports: Statistics Definitions

Following are defintions of STD DEV and NZ to help you better understand our Market Reports.

STD DEV:  In probability theory and statistics, the standard deviation of a statistical population, a data set, or a probability distribution is the square root of its variance. Standard deviation is a widely used measure of the variability or dispersion, being algebraically more tractable though practically less robust than the expected deviation or average absolute deviation. It may be thought of as the average difference of the scores from the mean of distribution, how far they are away from the mean. A low standard deviation indicates that the data points tend to be very close to the mean, whereas high standard deviation indicates that the data are spread out over a large range of values.

NZ (No Zero):  When calculating averages for numerous properties, there is always a chance that a property may have a null or zero value in an important field. Consequently, in order to get a true average for the data, the property with a zero is not included in the NZ calculation.