That's because a lot of VoIP services out there go by their product names and don't make a lot of noise about it. (That's not a big deal and they're not trying to hide it. For example, if you've heard of Skype, you've heard of one of the best-known Web-based VoIP services in use.
The Range Rule. The range rule tells us that the standard deviation of a sample is approximately equal to one fourth of the range of the data. In other words s = (Maximum â Minimum)/4.This is a very straightforward formula to use, and should only be used as a very rough estimate of the standard deviation.he Range Rule. The range rule tells us that the standard deviation of a sample is approximately equal to one fourth of the range of the data. In other words s = (Maximum â Minimum)/4.
When analysing normally distributed data, standard deviation can be used in conjunction with the mean in order to calculate data intervals. If = mean, S = standard deviation and x = a value in the data set, then. 1  about 68% of the data lie in the interval: .2  about 95% of the data lie in the interval: + 2S. 3  about 99% of the data lie in the interval: + 3S.hen analysing normally distributed data, standard deviation can be used in conjunction with the mean in order to calculate data intervals. If = mean, S = standard deviation and x = a value in the data set, then. 1  about 68% of the data lie in the interval: .