Sample of n elements selected from a population of A? elements in such a way that the sample has essentially the same characteristics as the population. The random sample serves as the foundation of all probability theory as it relates to probability in sampling. In theory, all subsets drawn from the same sample have an equal chance of being drawn. Sampling is extremely important to the calculation of premium rates. For example, if the insurer wants to predict the probability that a wood-frame house will burn, the sample must be drawn from the population of wood-frame houses, not brick-frame houses.