[R] Probit Analysis: Confidence Interval for the LD50 using Fieller's and Heterogeneity (UNCLASSIFIED)
Kenney, Colleen T CTR USA AMC
colleen.t.kenney at us.army.mil
Mon Nov 22 20:24:50 CET 2010
Classification: UNCLASSIFIED
Caveats: NONE
A similar question has been posted in the past but never answered. My
question is this: for probit analysis, how do you program a 95%
confidence interval for the LD50 (or LC50, ec50, etc.), including a
heterogeneity factor as written about in "Probit Analysis" by
Finney(1971)? The heterogeneity factor comes into play through the
chi-squared test for homogeneity and is equal to h=chi^2/(k-2), where k
is the number of doses and k-2 are the degrees of freedom.
I have done a lot of research on this and really appreciate any help
anyone can provide. Thank you!
Classification: UNCLASSIFIED
Caveats: NONE
More information about the R-help
mailing list