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

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