X̅ = 3.70
t.2 = 1.533
Σ(Xi − X̅)2 = .932
Sf = .394

The calculations are shown in table 6.

TABLE 5

Calculation of Confidence Intervals for Area
TribeXo(Xo − X̅)(Xo − X̅)2
---------------
Σ((Xi − X̅)2)
{ (Xo − X̅)2}
√{1/6 + ----------------}
{ Σ((Xi − X̅)2)}
{ (Xo − X̅)2}
t.2Sa × √{1/6 + ----------------}
{ Σ((Xi − X̅)2)}
Kato5.42-.23.0616.4778.263
Bear River4.80-.83.85101.0088.556
Lassik5.96.31.1119.5278.291
Nongatl6.751.101.40861.2551.692
Shelter Cove Sinkyone5.86.21.0513.4669.257

TABLE 6

Calculation of Fishing-Mile Estimates
TribeXo(Xo − X̅)(Xo − X̅)2
---------------
Σ((Xi − X̅)2)
{ (Xo − X̅)2}
√{1/6 + ----------------}
{ Σ((Xi − X̅)2)}
{ (Xo − X̅)2}
t.2Sf × √{1/6 + ----------------}
{ Σ((Xi − X̅)2)}
Kato3.37-.22.0281.4414.267
Bear River3.04-.55.1756.5851.353
Lassik3.22-.37.0795.4962.300
Nongatl4.44.85.4193.7655.462
Shelter Cove Sinkyone4.20.67.2160.6186.374

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.