Standard deviation from ungrouped data. The standard deviation is a summary measure of the differences of each observation from the mean. If the differences themselves were added up, the positive would exactly balance the negative and so their sum would be zero. Consequently the squares of the differences are added.
A pissant, also seen as piss ant or piss-ant, refers to a specific type of ant. The word is also used as a pejorative noun or adjective, indicating insignificance.he original pissant is any of a certain group of large ant species, commonly called wood ants, that make mounded nests in forests throughout most of Europe.
Fire ant is the common name for several species of ants in the genus Solenopsis. They are however only a minority in the genus, which includes over 200 species of Solenopsis worldwide.Solenopsis are stinging ants and most of their common names reflect this, for example, ginger ants and tropical fire ants.Many species also are called red ants because of their light brown colour, though species of ants in many other genera are similarly named for similar reasons.ire ants often attack small animals and can kill them. Unlike many other ants, which bite and then spray acid on the wound, fire ants bite only to get a grip and then sting (from the abdomen) and inject a toxic alkaloid venom called Solenopsin, a compound from the class of piperidines.