Averages, Standard Deviations

Average Standard deviation Average Standard deviation... 

Form Average Standard Deviation Average Standard Deviation Uptake (%)... 

Table 4-2 Evaluation of field tests [11] by class of soil (average standard deviation). ...

Number of measured points (N) = 95 ASD Average standard deviation of regression... 

Normally, the averaged standard deviation sav is estimated according to Eq. (4.42). If no information is given on nRM, it can be taken from the assumption that mostly nRM > 20. 

Sakamoto [243] determined picomolar levels of cobalt in seawater by flow injection analysis with chemiluminescence detection. In this method flow injection analysis was used to automate the determination of cobalt in seawater by the cobalt-enhanced chemiluminescence oxidation of gallic acid in alkaline hydrogen peroxide. A preconcentration/separation step in the flow injection analysis manifold with an in-line column of immobilised 8-hydroxyquinoline was included to separate the cobalt from alkaline-earth ions. One sample analysis takes 8 min, including the 4-min sample load period. The detection limit is approximately 8 pM. The average standard deviation of replicate analyses at sea of 80 samples was 5%. The method was tested and inter calibrated on samples collected off the California coast. 

Figure 2.15 Percentage of incorporated vancomycin released from discs of load 20mgg T as a function of time and water tetramethylorthosilicate (TMOS) molar ratio (R) (n — 3, errors bars represent 1 standard deviation). Average total vancomycin amount in discs of water TMOS molar ratio = 4 of load 20 mg g 1 was 8.5 mg per disc. (Reproduced from ref. 10, with permission.)...

The procedure [16] discussed in section 13.2.2.1 for the determination of alkyllead compounds in non-saline sediments has also been applied to marine sediments. Recoveries from sediments ranged from 94% for triethyllead to 111% for trimethyllead in the range l-20pg alkyllead spiked to lg of sediment. An average standard deviation of 4% for trimethyllead and triethyllead and 15% for dialkylead compounds was obtained. 

It is the distance from the mean to the point of inflexion of the normal distribution curve. In comparison to the average deviation the standard deviation is usually considered to be much more useful and meaningful statistically. For a finite number of values it is normally symbolised as S , and may be expressed as follows ... 

In general, data are fit quite well with the model. For example, with only two binary parameters, the average standard deviation of calculated lny versus measured InY of the 50 uni-univalent aqueous single electrolyte systems listed in Table 1 is only 0.009. Although the fit is not as good as the Pitzer equation, which applies only to aqueous electrolyte systems, with two binary parameters and one ternary parameter (Pitzer, (5)), it is quite satisfactory and better than that of Bromley s equation (J). 

STATISTICS At the end of the experiment the statistics (average, standard deviation, and chi-square) of each harmonic are computed. The data quality (precision and accuracy) depends on both the numbers of scans and the number of runs. 

Differences in measurement methods include analyzer systems based both on the same and on different measurement principles. The average standard deviation in the performance of different chemiluminescent ozone instruments that are sampling the same ambient air both with and without an added ozone concentration of 0.(X)2-0.5 ppm is 6-10%. Field studies comparing an ultraviolet monitor with several chemiluminescent monitors showed correlation coefficients for hourly averages of 0.80-0.95 between various pairs of instruments. Hourly averages for about 500 pairs of values at ambient ozone concentrations of 0.005-0.100 ppm showed deviations of 3-23% between the average values for paired instruments. 

Table VII. Average corrosion rate of steel, standard deviation, average Chloride deposition rate, standard deviation and aerage TOW-... 

Property Average Standard deviation (SD) SD/Ave (%) Maximum Minimum Range... 

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