Title: New list is open
Good day everyone,
Around 20% of the members have now moved to the new list and we should then to start to use it. Remember the new address of the list is ai-geostats@jrc.it
The rules have not changed.
I am sorry the move of the list was so chaotic but the
Is it correct that the probability of being above or below
the mean of a skewed
distribution is not necessarily 0.5?
Yes-
Take a gold deposit with 99% of assays 0
gpt, 1% of assays 1 gpt. Mean is 0.01, prob 1 assay mean =99%
Extreme case but true for lognormal as
well.
Robert (Bob) L. Sandefur PE
Senior Geostatistician / Reserve Analyst
CAM 200 Union Suite430
Lakewood,
Co
80228
[EMAIL
AI-GEOSTATS
On 19-May-06 Digby Millikan wrote:
Is it correct that the probability of being above or below
the mean of a skewed distribution is not necessarily 0.5?
Very much true that it may not be 0.5!
As a general (though not absolutely true) rule, if a distribution
is positively skewed then
DigbyIf your distribution has a positive skewness as calculated (bulks towards zero with long tail into high value) the proportion below the mean will be significantly higher than 50%. If negatively skewed -- e.g. Calcium in limestone, iron in iron ore -- more than 50% will be above the mean.
