Method: Statsample::StratifiedSample.proportion_variance_esd_wor

Defined in:
lib/statsample/multiset.rb

.proportion_variance_esd_wor(es) ⇒ Object 



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# File 'lib/statsample/multiset.rb', line 188

def proportion_variance_esd_wor(es)
  n_total=n_total=calculate_n_total(es)
  
  sum=es.inject(0){|a,h|
    a=(h['N']**2 * (h['N']-h['n']) * h['p']*(1.0-h['p'])) / ((h['n']-1)*(h['N']-1))
    a+val
  }
  Math::sqrt(sum) * (1.0/n_total**2)
end