In a batch of candies produced in the Skittles factory, there are equal amounts of the five colors all mixed together before being packaged into separate bags. Consequently, each color should represent approximately 20 percent of any one skittles bag.
However, due to occasional errors in the mixing process, each small sample of the overall batch will likely have deviations from the 20 percent that each color should represent. In a perfect world, the candy batch would be completely uniform before packaging, resulting in the perfect proportion of Skittles for each bag. Because errors result in minor deviations, Skittles' consumers can expect to have anywhere from a 15 to 23 percent composition of any color when they open their bag.