It is defined as the positive square root of the mean of the squared deviations from mean. The square of S.D is called variance.
The standard deviation is used as a measure of the variance of a measurement within a group of objects. In essence, it is the average difference between the measurement of any one object and the mean measurement for the group. For example, if the average measured weight of brown bears is 140kg (265lbs) and the standard deviation of weights among brown bears is 5kg (11lbs), then any particular, individual brown bear is likely to weight between 135-145kg (254-276lbs), and very likely to weight between 130-150kg (243-287lbs). It's impossible to know the weight of an individual bear just by looking at the mean weight for all bears, but the standard deviation tells you what range of weights the weight of an individual bear will fall in.
How many standard deviations is 16.50 from the mean?
You can't average means with standard deviations. What are you trying to do with the two sets of data?
That depends on what the standard deviation is.
It is mean + 2*standard deviation.
standard deviations
How many standard deviations is 16.50 from the mean?
The sum of standard deviations from the mean is the error.
All minor deviations occurring with two standard deviations under the Gaussian curve are considered normal. Deviations occurring outside of two standard deviations are considered abnormal.
95% is within 2 standard deviations of the mean.
The mean for the WISC, like the WAIS, is 100. The deviations from 100, or standard deviations, are 15.
You can't average means with standard deviations. What are you trying to do with the two sets of data?
2 times the standard deviation!
That depends on what the standard deviation is.
standard deviations
Z-Score tells how many standard deviations a measurement is away from the mean.
I believe the standard deviations are measured from the median, not the mean.1 Standard Deviation is 34% each side of median, so that is 68% total.2 Standard Deviations is 48% each side of median, so that is 96% total.
You cannot have a standard deviation for 1 number.