Errors of Histograms -- II

• In a poll of 1,000 people, one finds that 25% are in lth bin (i.e., will vote for xyz).

  

• Thus, error in estimate of fraction voting for xyz is ---this is STATISTICAL error only.

• The systematic bias (is ``1,000'' chosen people representative) is a harder problem!

• As not that small, should reduces statistical error by

  

  using equations (fulle), not (approxe).