Technique: How To Use A Multimeter. Learn to use a multimeter to test voltage, resistance, and continuity. Every fixer should know their way around a multimeter, which has just north of a zillion uses for testing electronic components and circuits. Follow along to master the three most basic functions of a multimeter.
It is more generally a measure of spread. The mean is a measure of location. The ratio of the standard deviation to the mean is called the coefficient of variation. This can be helpful in distinguishing two data sets that are given in different units.For example if we are comparing economic data from two different countries, the data might be quoted in different currencies. similar ratio is the index of dispersion, which is the square of the standard deviation divided by the mean. In biology, for example, we might look at the locations of trees within a wood. An index of dispersion equal to 1 would indicate a dispersal consistent with a Poisson process, i.e. uniformly at random.
The row labeled 'difference between means' shows just that: The difference between the mean of group A and the mean of group B. It also reports the standard error of that difference. That is used to compute the confidence interval for the difference between the two means, shown just below. The standard error for the difference between two means is larger than the standard error of either mean. It quantifies uncertainty. The uncertainty of the difference between two means is greater than the uncertainty in either mean. So the SE of the difference is greater than either SEM, but is less than their sum.