characteristic of demand
The smaller the standard deviation, the closer together the data is. A standard deviation of 0 tells you that every number is the same.
The "z-score" is derived by subtracting the population mean from the measurement and dividing by the population standard deviation. It measures how many standard deviations the measurement is above or below the mean. If the population mean and standard deviation are unknown the "t-distribution" can be used instead using the sample mean and sample deviation.
Standard Deviation
It shows primarily that the measurement unit used for recording the data is very large. For example, the standard deviation of the heights of individuals, when recorded in metres, will be one hundredth of the standard deviation of their heights when recorded in centimetres. The process is known as coding.
Standard deviation has the same unit as the data set unit.
One can't associate a standard deviation with a single measurement like this.
The standard deviation tells us nothing about the mean.
characteristic of demand
The smaller the standard deviation, the closer together the data is. A standard deviation of 0 tells you that every number is the same.
The standard deviation has the same measurement units as the variable and is, therefore, more easily comprehended.
The answer depends on the individual measurement in question as well as the mean and standard deviation of the data set.
The "z-score" is derived by subtracting the population mean from the measurement and dividing by the population standard deviation. It measures how many standard deviations the measurement is above or below the mean. If the population mean and standard deviation are unknown the "t-distribution" can be used instead using the sample mean and sample deviation.
Standard Deviation
It is a measure of the spread of the distribution. The greater the standard deviation the more variety there is in the observations.
The mean and standard deviation often go together because they both describe different but complementary things about a distribution of data. The mean can tell you where the center of the distribution is and the standard deviation can tell you how much the data is spread around the mean.
They are effectively the same but the standard deviation is more popular because the units of measurement are the same as those for the variable.