Wrapping up Wrisc.
The author of RISC lent us the trial version, and it clearly has some bugs in it. The Monte Carlo does not work in Windows 98 or 2000, nor the help screens work in 2000. I also noted that running an input file gave different or anomalous results, depending on what was in the defaults when the file was open. Although running it again did give consistent results. The earlier versions of RISC did not have these problems, and I'm sure this latest version will be OK, when the bugs are worked out. I wanted to show you a little about inputting on point data and Monte Carlo.
Monte Carlo
As you worked through RISC you came across several options we did not use. In the Source Concentrations, we used a single value. You can also put in all your lab data and let RISC average it for you. Here are the input screens:
Arithmetic average and using the 95% upper confidence level (UCL)(based on the t-test),we did in 10A. Geometric and 95th UCL Lognormal are similar if the log of the data is "more normal" than the data itself. You could also assign a weight to the data, say one sample is 5 times more important than the others, you could weight it at 5 and the others at 1.
For handling the non-detects we are offered some choices as well:
However once we are all done inputting the data and the machine averages it, RISC will then chug through using the computed average.