English to Polish Other Environment & Ecology general

Tekst o badaniach mikrobiologicznych wody.

The Poison index of dispersion (χ2𝑟−1) is compared to the Chi squared distribution critical 0.05 (95.0%) probability value for the appropriate degrees of freedom (in this case 10 – 1 = 9) which for this example equals 16.92. As the index of dispersion for sample 1 (30.58) is greater than this Chi square value, significant over-dispersion for this set of repeated measurements has been detected. Ideally, the dispersion should be within the Poisson distribution (i.e., χ2𝑟−1 < 16.92) but it is common for count dispersions for microbiological methods to be over-dispersed. Thus, the extent of the over-dispersion in terms of repeatability is calculated.