722
HAWTHORNE
Table 3 NUMBER OF SPECIMENS* REQUIRED FOR STATED
PRECISION+ IN ASSESSMENT OF 8'Cs
Confidence level
0.90
0.95
2
33
2
46
Soil, 0 to 1 in. deep
Kg/m?
Pe/kg
Pe/m?
11
Alfalfa
Kg/m?
3
Pc/kg
50
Pe/m?
43
Milk
Kg/milking
2
Pc/ milking
9
Pe/kg
8
15
4
70
60
3
12
13
0.99
4
79
26
6
121
103
4
20
22
*Size of sample = (ZC/P)*, where Z is the confidence-level
constant, C is the standard deviation/mean, and is the precision level.
* Precision level used was +10% of the mean.
that assumptions of general homogeneity were unwarranted. Since the
ultimate objective of the study is to construct mathematical models of
the cycles of Sr and "Cs, measurements of the amounts of *’Sr and
ICs present are required. The point to be made here is that definition
of the amounts of fission products in the system is subject to an uncertainty that varies in time and three-dimensional space. The system is
dynamic. Mathematical models of the system must takethese variations
into account. A stochastic model is required. It must be constructed
from actual observations upon the system over some time interval instead of upon assumptionsif it is to be realistically definitive.
REFERENCES
1. Health and Safety Laboratory, Manual of Standard Procedures, USAEC Report
NYO-4700(Rev.), August 1962.
2. W. J. Dixon and F. J. Massey, Jr., Introduction to Statistical Analysis,
McGraw-Hill Book Company, Inc., New York, 1957.
3. G. W, Snedecor and W. G. Cochrane, Statistical Methods Applied to Experiments in Agriculture and Biology,
Sth
ed.,
lowa
State
University
Press,
Ames, Iowa, 1956.
4. W. G. Cochrane and G. M. Cox, Experimental Designs, John Wiley & Sons,
Inc., New York, 1950.
5. A. Wald, Sequential Analysis, John Wiley & Sons, Inc., New York, 1947.
My