Adjustment Computations, 6th Edition

CHAPTER 4CONFIDENCE INTERVALS

4.1 INTRODUCTION

Table 4.1 contains a discrete population of 100 values. The mean (μ) and variance (σ²) of that population are 26.1 and 17.5, respectively. By randomly selecting 10 values from Table 4.1, an estimate for the mean and variance of the population can be determined. However, it should not be expected that these estimates ( and S²) would exactly match the mean and variance of the population. Sample sets of 10-values each could continue to be selected from the population to determine additional estimates for the mean and variance of the population. However, it is just as unlikely that these additional values would match those obtained from either the population or the first sample set.

TABLE 4.1 Population of 100 Values

18.2	26.4	20.1	29.9	29.8	26.6	26.2
25.7	25.2	26.3	26.7	30.6	22.6	22.3
30.0	26.5	28.1	25.6	20.3	35.5	22.9
30.7	32.2	22.2	29.2	26.1	26.8	25.3
24.3	24.4	29.0	25.0	29.9	25.2	20.8
29.0	21.9	25.4	27.3	23.4	38.2	22.6
28.0	24.0	19.4	27.0	32.0	27.3	15.3
26.5	31.5	28.0	22.4	23.4	21.2	27.7
27.1	27.0	25.2	24.0	24.5	23.8	28.2
26.8	27.7	39.8	19.8	29.3	28.5	24.7
22.0	18.4	26.4	24.2	29.9	21.8	36.0
21.3	28.8	22.8	28.5	30.9	19.1	28.1
30.3	26.5	26.9	26.6	28.2	24.2	25.5
30.2	18.9	28.9	27.6	19.6	27.9	24.9