Custom Search
|
|
|
||
 Sample Size
Sample
Size
Month
Calculation
to use
1
560 x 159
183.97
184
484
2
560 x 166
192.07
193
484
3
560 x 159
183.97
184
484
Total
560.00
561
(h) Selecting the Sample from the Population. Having determined the
size of the Sample, the sample is selected from the population. A series of
random numbers equal in number to the sample size are generated either by
using the RSED computer program or the random number table shown in Appendix
F, Table 4. (The use of the RSED computer program is preferable to the use
of the random number table. The use of the tables is discussed in Appendix F
for somewhat academic reasons.) These random numbers are matched against
the population numbers which were obtained when the population was
sequentially numbered as shown at 4-600 to determine the population numbers
to be inspected .
Example: Five garbage containers are to be emptied twice a week, Monday
and Thursday. At 4-620 the population was determined to be 40 based on the
January 1988 calendar with sequential numbers starting at 101 and ending
with 140 assigned to each pickup. For the purpose of this example, assume
we wish to select a total sample size of 5. Using the random number table
in Appendix F, Table 4, five random numbers would be generated between 1O1
and 140. The five numbers generated were 110, 122, 130, 132, and 138. By
referring to the listing of the sequentially numbered population at 4-620,
the container number and the date of inspection is determined and a sampling
schedule is developed as follows:
Inspection
Container
Population
Number
Number
Number
Date
1
110
7
5
2
122
18
2
3
130
21
5
4
132
25
2
5
138
28
3
The scheduling schedules are shown in the surveillance guides for each
contract requirement. A typical surveillance guide is shown in Appendix G.
(i) Evaluation Process. List any procedures or checklists used when
doing the inspection. Evaluation procedures should be in enough detail to
allow others to continue the same manner of inspection using the same
86
|
 
|
|
|
||
