Normal standard detion true is-

Repeated question the standard detion (SD, also represented by the Greek letter sigma s or the Latin letter s) is a measure that is used to quantify the amount of variation or dispersion of a set of data values. A low standard detion indicates that the data points tend to be close to the mean (also called the expected value) of the set, while a high standard detion indicates that the data points are spread out over a wider range of values