What is the chi-squared test? The chi-squared test, often written as χ 2 test, is a statistical hypothesis test used in the analysis of categorical variables to determine whether observed data are ...

The purpose of this paper is threefold. First, the exact nature of the research hypothesis being tested will be discussed, which will lead directly into the notion of directional and nondirectional ...

In this article we study how to approximate a random variable T of general chi-squared—type mixtures by a random variable of the form $\alpha \chi _{d}^{2}+\beta ...