Question

When testing water for chemical impurities, results are often reported as BDL, that is, below detection limit. The following are the measurements of the amount of blood in a series of water samples taken from inner - city households (in parts per million):
5, 7, 12, bdl, 10, 8, bdl, 20, 6

Answer 1

Answer:

The median level in the water is 7ppm

Explanation:

LoB is assessed by calculating duplicates of a blank sample and evaluating the mean result and the standard deviation (SD). After evaluating this value LOD can be evaluated conferring to LOD=LOB+1.645(SD low concentration sample ). The quantitation limit can also be got from accuracy studies. LOD's may also be evaluated based on the standard deviation of the response (Sy) of the curve and the slope of the calibration curve (S) at levels resembling the LOD according to the formula: LOD = 3.3$\frac{Sy}{S}$