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Manual for psimpoll and pscomb

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Menu N: confidence intervals

Menu N2: method
This option affects the method of calculating confidence intervals for concentrations and accumulation rates:
1 Modification of Maher's lognormal distributions
2 Propagation of errors
N2.1
this method follows Maher (1981), with additional use of propagation of errors methods (Parratt 1961). It produces confidence intervals that are asymmetric (i.e., wider above the calculated value).
N2.2
this method follows a propagation of error method (Parratt 1961; Squires 1985) throughout the calculation. Confidence intervals are almost identical to those obtained by Maher's method, but are symmetric about the calculated point. This means that the lower interval may extend to the negative side of the axis.

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