From: [EMAIL PROTECTED] (Simon, Steve, PhD)
>For a lognormal distribution, the left tail can often be approximated by a
>triangular distribution. The median of a triangular distribution is the
>upper limit divided by the square root of 2.
>
>There are more sophisticated approaches, of course, to
[EMAIL PROTECTED] writes:
>"Analyte concentration levels less than the limit of detection
>were assigned a value equal to the detection limit divided by the
>square root of 2 for calculation of geometric mean values.
>
>There must be a simple reason for the sqrt(2), but I'm not seeing it.
>Can so
This may be a simple question on how to handle non-detects in analysis:
The CDC just released an important survey of chemicals in humans:
http://www.cdc.gov/nceh/dls/report/default.htm
One part of the data analysis piqued my interest, how non-detects were handled:
On the following page:
http://ww
