Advanced Engineering Design

Appendix: statistical concepts

The numbers used by a designer (values used as data or results) are normally affected by noise and inaccuracies that turn them into random variables. Thus, the values taken by the variable y at a particular moment form a set {y₁,…,y_N}, which we will refer to as an N-sized sample. These values also belong to a larger set, called a population, whose elements are all the possible results that could appear in the sample.

The elements of the population have a particular possibility of appearing in a sample. We use the term probability distribution to refer to the function that assigns each element of the population a probability of appearing in an N = 1-sized sample. The mean (population mean) and variance (population ...