An estimate of the average intake of 239,240py per day by a cow grazing the inner compound is computed from average 239,240by concentrations for shrubs Eurotia lanata and Atriplex canescens. This result (620 + 130 nCi/day) agrees quite well with the 560 nCi/day estimated by Smith et al. (1976a) using average 239,240p, activities in the vegetation and liquid components of rumen contents of fistulated steers grazing the inner compound of Area 13. An estimate of 770 nCi/day was obtained using Martin and Bloom's model assuming 500 grams of soil is ingested per day by grazing cattle. The second part of this paper discusses some aspects of displaying and analyzing skewed data sets. Some relationships between the arithmetic mean, geometric It is shown that estimates of inventory mean, median, and mode are discussed. can be greatly influenced by the particular measure of central tendency (average) The point is made that the choice of used to characterize a skewed data set. a measure of central tendency depends on the objective of the study and the Stem-and-leaf displays for displaying the use to be made of the estimate. information content of a data set are discussed and illustrated using soil and rodent plutonium concentrations. The third and final portion of this paper reviews some of the bias problems we have encountered in attempting to estimate plutonium concentration contours in Area 13 (Project 57) and Area 5 (GMX site). The possibility of estimating inventory by first estimating the spatial pattern of plutonium concentrations in surface soil is suggested. An evaluation of Universal Kriging for this purpose is encouraged. Finally, some estimated contours for Area 5 (GMX) are displayed to illustrate what appears to be improved estimates using log-trans- formed data. Contours obtained using polynomial fits are shown to be susceptible to large biases in areas of the study site where few data were collected. FUTURE PLANS We expect to: 1. Continue to provide statistical help in the synthesis of safety-shot data for 239Pu and for other radionuclides (238py, 24 lam, 238y), 2. Continue our assistance to program investigations in the analysis of 3. Help design environmental transuranic studies at nuclear sites on NTS. 4. Identify or develop efficient field sampling designs for estimating spatial patterns (geographical distribution). 5. Continue to experiment with estimating Pu concentration contours using their data. computer algorithms. 270