A value close to -1 indicates a negative linear correlation; that is, when one variable increases the other decreases. A value close to 0 indicates a non-linear, or random, correlation. The equation for calculating the correlation coefficient is where Xi and Yi are the set of variables, and the sample means.
A demographic is a subset of a population that shares a common factor such as age, income or education level. The Millennial generation, for example, is the demographic cohort that immediately follows Generation X. Although there is a great deal of variation from one individual to another within any generational cohort, the particular environment for any generation affects those individuals in ways that are observable as broad tendencies.
1 Population and sample. In statistics, a population is an entire set of objects or units of observation of one sort or another, while a sample. is a subset (usually a proper subset) of a population, selected for particular study (usually because it is impractical. to study the whole population).