chi-square distribution

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chi-square dis·tri·bu·tion

a variable is said to have a chi-square distribution with K degrees of freedom if it is distributed like the sum of the squares of K independent random variables, each of which has a normal (gaussian) distribution with mean zero and variance one. The chi-square distribution is the basis for many variations of the chi-square(d) test, perhaps the most widely used test for statistical significance in biology and medicine.
References in periodicals archive ?
Not surprisingly, agricultural sales revenue was significantly associated with hectarage (chi squared 332.9801, 20df, p [is less than] 0.000).
Interestingly, while agricultural sales revenue was significantly associated with hectarage, farm profitability was not (chi squared 12.4954, 8df, p [is less than] 0.13), indicating a strength of small-scale agricultural production.
Farms with larger hectarage were more likely to have both increased and decreased the number of managers (chi squared 23.0211, 4df, p [is less than] 0.000 and chi squared 19.4295, 4df, p [is less than] 0.000 respectively) and to have increased their own time in managing and business planning (chi squared 22.5779, 4df, p [is less than] 0.000 and chi squared 30.1026, 4df, p [is less than] 0.000 respectively).
Chi squared tests for contingency tables with proportions estimated from survey data.