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    Re: Round-off
    From: Peter Fogg
    Date: 2009 May 15, 12:34 +1000

    John Karl wrote:
    This question is more a matter of navigational philosophy.  I
    subscribe to the old adage that it's most important to know where you
    are not, i.e., DEFINITELY where you are not.  And that's not a matter
    of statistics.  I'm not satisfied to miss reefs only a percentage of
    the time.  So I look at the maximum round off error. Rounding every
    one of 12 numbers to the nearest whole minute could lead to a maximum
    error of about 0.4'x12 = 4.8'.  Why introduce this possible error when
    it's completely unnecessary?
    I think the simple answer is that for practical reasons you have to give consideration to how probable error leading to risk is.   A statistical analysis can do this.  Risk can thus be usefully evaluated, leading to an informed decision as to action, if any.
    If you considered that the maximum potential risk should always be applied then I don't think you would go sailing at all.

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