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.
Itchy rash all over body. Universally called itching, pruritus is described as an unpleasant feeling which causes individuals to scratch a body area. This may be localized or generalized. When pruritus is accompanied with a body rash, the cause must be established and promptly treated. Toxin accumulation is one main culprit in sudden appearance of a generalized itchy rash. Its manifestation signifies that there is something going on in the body. Another great cause is when the body area is not appropriately cleansed; as a result, sweat and dirt build up on the skin resulting to irritation.