Entomology for beginners. Entomology is the study of insects. This page provides some basic information on insects. First we look at the anatomy of adult insects, and then we will see a short story about the metamorphosis of insects. Insect anatomy.
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.
Standard deviation is calculated based on the mean. The distance of each data point from the mean is squared, summed and averaged to find the variance. Or to put it another way: Variance is derived by taking the mean of the data points, subtracting the mean from each data point individually, squaring each of these results and then taking another mean of these squares.