Introduction. The standard deviation is a measure of the spread of scores within a set of data. Usually, we are interested in the standard deviation of a population. However, as we are often presented with data from a sample only, we can estimate the population standard deviation from a sample standard deviation.ntroduction. The standard deviation is a measure of the spread of scores within a set of data. Usually, we are interested in the standard deviation of a population. However, as we are often presented with data from a sample only, we can estimate the population standard deviation from a sample standard deviation.
Itching usually results from dry skin, a skin disorder, or an allergic reaction. If the person has no rash or skin abnormalities, the cause may be a drug, an allergic reaction that has internal effects, or a systemic disorder.
These rashes tend to be only an external problem, however a rash that covers your whole body can be a sign of internal health issues. Whether it suddenly appears or is slowly spreading, a rash all over your body should be examined by a doctor to pinpoint the underlying cause. Digestive disorders, thyroid problems, drug reactions and certain cancers are the four main causes of rashes that spread all over the body. Digestive Disorders There are a number of digestive system disorders that can lead to a full body rash.