___________________________ {1 (X_{o} - [=X])^2 } D = [Sqrt]{- + ---------------------} {6 =S=((X_{i} - [=X])^2)} ___________________________ {1 (X_{o} - [=X])^2 } E = t_{.2}S_{f} × Sqrt{- + ---------------------} {6 =S=((X_{i} - [=X])^2)} =========================================================== | Tribe | [A] [B] [C] [D] [E] ______________________|____________________________________ | Kato | 3.37 -.22 .0281 .4414 .267 Bear River | 3.04 -.55 .1756 .5851 .353 Lassik | 3.22 -.37 .0795 .4962 .300 Nongatl | 4.44 .85 .4193 .7655 .462 Shelter Cove Sinkyone | 4.20 .67 .2160 .6186 .374 The results of the calculations are given in table 7. The figures are point estimates with 80 per cent confidence intervals. This means that under the assumptions given earlier we expect that the tabled intervals will contain the true population 8 times out of 10. I have accepted the estimates derived from fishing miles because their confidence intervals are a bit shorter on the average. TABLE 7 _Population Estimates and Confidence Intervals_ Fishing-mile Area Tribe Estimate Estimate ---------------------|-------------------|------------- Kato |1,523 ± 267 | 1,470 ± 263 Bear River |1,276 ± 353 | 840 ± 556 Lassik |1,411 ± 300 | 2,020 ± 291 Nongatl |2,325 ± 462 | 2,830 ± 692 Shelter Cove Sinkyone|2,145 ± 374 | 1,920 ± 257 ---------------------|-------------------|------------- The question of whether the fishing-mile estimates yield shorter confidence intervals than the area estimates brings up an entire range of problems pertaining to economy, settlement pattern, and the like. The obvious interpretation of the shorter confidence intervals would be that the economy of the people in question depended more on fish and fishing than on the general produce over the whole range of their territory. The question then becomes one of quantitative expression--we would like to have some index of the extent of dependence on various factors in the economy. This might best be approached from the standpoint of analysis of covariance, where we would obtain the "components of variance." This technique is a combination of the methods of regression used in this paper and those of the analysis of variance. It would evidently yield sound indices of economic components, but it involves, for myself at least, certain problems of calculation and interpretation which will have to be resolved in the future.