It means that particular observation is close to the population [or sample] mean.
You cannot. If you are told the standard deviation of a variable there is no way to tell whether that was derived from grouped or ungrouped data.
The smaller the standard deviation, the closer together the data is. A standard deviation of 0 tells you that every number is the same.
How widely spread out, or tightly concentrated about the mean it is.
Did you mean to ask: "What is standard deviation, and what are it's advantages and disadvantages" ? Standard deviation is a measure of how "spread out" a set of data is. If it is large, you have a large range of numbers. If it is small, most of your data points are close to the average. To find it, you need to subtract the "mean" (average) of the data from each data point, square your answers, add them all together, divide your answer by the number of data points minus 1, and take the square root. For a better explanation of how to find it, have a look here, see the related link below. So it's advantage is, it gives you a better picture of your data than just the mean alone. Disadvantages would be that it doesn't tell you the full range of the data, and it can be effected by "outliers" (rare numbers much smaller or larger than everything else in the data set) to give a skewed picture.
i dont know...... it means
It is a measure of the spread or dispersion of the data.
It means that particular observation is close to the population [or sample] mean.
it tells you
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.
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You cannot. If you are told the standard deviation of a variable there is no way to tell whether that was derived from grouped or ungrouped data.
The mean deviation is a measure of dispersion that calculates the average absolute difference between each data point and the mean. One advantage of mean deviation is that it considers every data point in the calculation, providing a more balanced representation of the data spread. However, a disadvantage is that it can be sensitive to outliers, as it does not square the differences like the variance does in standard deviation, making it less robust in the presence of extreme values.
The standard deviation tells us nothing about the mean.
The smaller the standard deviation, the closer together the data is. A standard deviation of 0 tells you that every number is the same.
It tells you how much variability there is in the data. A small standard deviation (SD) shows that the data are all very close to the mean whereas a large SD indicates a lot of variability around the mean. Of course, the variability, as measured by the SD, can be reduced simply by using a larger measurement scale!
standard deviation is the square roots of variance, a measure of spread or variability of data . it is given by (variance)^1/2