3. CONFIDENCE INTERVAL

1. Sampling error would indicate
    that the standard error provides
    an evaluating of the likely error
    associated with a particular
    estimate.

2. This interval is called an interval
    estimate [or confidence interval]
    where the interval is centred at the
    point estimate for the population
    mean.

3. From our knowledge of the normal
    distributions we know that 95% of
    the distribution lies within + - 1.96
    standard deviations of the mean.