AS 2891.14.15:2018 pdf free download – Methods of sampling and testing asphaltMethod 14.15: Mean, standard deviation coefficient of variation and characteristic values

AS 2891.14.15:2018 pdf free download – Methods of sampling and testing asphaltMethod 14.15: Mean, standard deviation coefficient of variation and characteristic values.
3 GERAL
When any or all of the mean, standard desiation. coefficient of variation and characteristic values of a set of test results are to be determined, they shall be calculated in accordance with this Standard. It shall be permissible to rcject abnormal test results bclore performing the calculation. A result may be assessed as being abnormal only if a specific reasoit for its abnormality is clearly evident (see Main Roads Western Australia Engineering Road Nutc 8). The reason for its rejection shall be reported.
In practice, specifications may require that test sites for each result be essentially randomly selected in accordance with an appropriate test method such as AS 1289.1.4.1 or
AS 1289.1.4.2.
The actual statistical values to be calculated will depend on the specification requiremcnts
Individual results obtained in the appropriate test shall not be rounded before use in calculations.
As the results to be reported have been subject to statistical analysis, they shall be reported to a greater precision than that indicated in the individual test methods, but to not more than one extra significant figure (for example. for density ratio determined in accordance with AS/NZS 2891.14.5 where individual results are reported to the nearest 0.5%, the statistical values may he reported to the nearest 0.1%).
Calculate the following, as required:
(a) The mean of the individual test results .
b) from the following equation.