The chi-square statistic (χ2) is a measure of the difference between the observed and expected frequencies of the outcomes of a set of events or variables.

Non-linearity is a mathematical term that describes a situation where the relationship between the independent variable and the dependent variable cannot be predicted along a straight line.

The Poisson distribution, named after the French mathematician Siméon Denis Poisson, can be used to estimate how many times an event can occur within “X” time periods.

The posterior probability in Bayesian statistics is the revised or updated probability of an event occurring after new information has been taken into account.

Unconditional probability reflects the probability that some event will occur without taking into account any other possible influences or previous results.

The 90/10 retirement investment strategy involves investing 90% of investment capital in low-cost S&P 500 index funds, and the remaining 10% in short-term government bonds.

The annual equivalent rate (AER) is the actual interest rate on investments, loans or savings accounts that can be obtained after compounding interest.