ok good news
& just the help i needed & sought
therefore please see my further improvements inserted below
--- In
BoundaryPoint@yahoogroups.com, Michael Kaufman
<mikekaufman79@y...> wrote:
> Not 16:1. You can't do math with odds very well.
ah but thanx to you i think i can now
provided you can also answer my additional question at the end
> Think in terms of probabilities. I'm assuming you
> figured a 1/5 chance for each of the two digits to be
> either 0 or 5. So you said 4:1 odds on each digit.
> But you can't simply multiply them. You can however
> multiply the probabilities together. (1/5) * (1/5) =
> 1/25. Another way to look at it is there are 4
> chances out of 100 for a 0 or 5 to come up in each of
> the two digit slots (0 and 0, 0 and 5, 5 and 0, or 5
> and 5). 4/100 is again 1/25. So this is the
> probability you need to know.
>
> --- aletheia kallos <aletheiak@y...> wrote:
>
> > well doc & dave &al
> > i think i have finally done it
> >
> > extracted the ultimate computational truth out of
> > bcidwa
> > thanxxx also to you all
> >
> > but it is still in rather long winded format
> > so please keep bearing with me
> > & maybe you can help improve it too
> >
> >
> > to begin with
> > cribbing from the comparatively finer but sketchier
> > table of geodetic constants at lower right in
> >
>
http://www.convertit.com/Go?ConvertitReference/AMS55.ASP?Re
s=150Page=8
> > i have computed the length of a minute of latitude
> > at
> > the 49th parallel as 1853meters plus 508mm
> >
> > & borrowing directly from the coarser but busier
> > table
> > in
> > http://home.online.no/~sigurdhu/Grid_1deg.htm
> > i have it as 1853meters plus 500mm
> >
> > so which is truer
> > & how many digits are reliable in any case
> >
> > but no matter
> > as these are only idle if still interesting
> > questions
> > since both produce fully significant centisecs of
> > 1 point 01351feet
> > & thats plenty significant
> >
> >
> > also
> > parenthetically
> > & only for later use
> > they produce fully significant millisecs of
> > zero point 101351 foot
> >
> >
> >
> > but so anyway for starters
> > this true centisec length in 6 significant digits
> > rather than just a plain approximate statute foot is
> > the true breadth of the swath cut by the ibc
> > centisec
> > coord ribbon between monuments 194 & 195
> >
> >
> > a n d
> >
> > in
> >
> http://groups.yahoo.com/group/BoundaryPoint/message/14910
> >
> > i was wrong to needlessly dumb down the plaque
> > coords
> > to the level of the ibc coords
> >
> > but by the same token i think it would also be rash
> > to
> > trust the millisecs expressed on the plaque as
> > anything more than actual demicentisecs
> > since their final significant digits are
> > suspiciously
> > 5 & 0 respectively
> > & together present a 16 to 1 probability that they
> > are
> > not significant millisecs at all
> > but only significant demicentisecs
not 16 to 1
but a 1 in 25 probability
or actually a 24 to 1 shot
dont you agree
> > for these could easily prove to have been
> > ambiguously
> > &or overconfidently stated on the plaque in nad83
> > & thus could have been overconfidently converted
> > into
> > nad27 by me
> > with 1 full additional significant digit each
> > as
> > nlat 48d 59m 57s 357 & wlong 117d 01m 52s 848
> > when the likelier value ranges 5 full millsecs
> > between the 355th & 360th millisec actually
> > of the 58th second of the final minute of the 49th
> > degree of latitude
> > in the case of the datum we will need to use here
> >
> >
> > but by taking into account both the major & the
> > minor
> > probability & weighting them proportionally
> > since neither can be dismissed out of hand
> > & since their relative likelihoods can also be
> > conveniently & precisely computed
> > we can indeed now improve the accuracy of the
> > placement of our intermonumental caus swath across
> > the
> > idwa meridian no less than we have improved the
> > accuracy of the measurement of its width
> >
> >
> > so
> > recalculating the ratios in
> >
> http://groups.yahoo.com/group/BoundaryPoint/message/14912
> >
> > to the limit of their actual applicability
> > we find that the centisec swath as stated above in
> > millifeet would be centered on the idwa meridian
> > exactly 4 point 7379807692 centisecs south of the
> > latitude of monument 195
> > which is to say
> > at precisely nlat 48d59m57s37262019231
> > on a flat earth
> >
> > or comfortably down to the 373rd millisec anyway on
> > the geoid
> >
> >
> > & therefore
> > the center of the truest or at least likeliest
> > available bcidwa centisec swath of width 1 point
> > 01351
> > feet
> > or 12 point 16212 inches
> > lies between 13 & 18 millisecs north of the 1909
> > disk
> > center
> >
> > or in better words
> > between 1 point 317563 & 1 point 824318 feet north
> > of
> > it
> >
> > or in still easier words to understand
> > between 15 point 810756 inches north of it
> > & 21 point 891816 inches north of it
> >
> >
> >
> >
> > therefore the better of the 2 best available guesses
> > for true bcidwa is centered 18 point 851286 inches
> > north of the 1909 disk center
> > plus or minus 6 point 08106 inches
> > & the caus centisec swath therefore most
> > probabalistically crosses the idwa meridian between
> > 12
> > point 77022 & 24 point 93234 inches north of the
> > 1909
> > disk center
> >
> >
> >
> > if however we knew the plaque coords were true
> > millisecs
> > an eventuality which is actually a 16 to 1 long shot
again
actually a 24 to 1 shot
do you agree
> > we could then confidently say the swath was centered
> > more nearly exactly 15 millisecs north of the disk
> > center rather than ranging so crudely 13 to 18
> > millisecs north of it
> >
> > & in this event the truest available bcidwa would be
> > centered 18 point 24318 inches north of it
> > & thus midway between swath edges lying
> > 12 point 16212 inches north of it
> > & 24 point 32424 inches north of it
> >
> >
> > so we can congratulate ourselves twice
> >
> > once for nailing the major & once for the minor
> > premise
& again for finally getting the math right
if indeed we have
> > & for a last hurrah
> > combining both these premises into one
> > we get a slightly expanded range
> > extending a bit more than a full centisec now
> > between 12 point 16212 inches north of it
> > & 24 point 93234 inches north of it
> >
> > but as for the best guessed single point in that
> > range
> > most interestingly
> > by weighting & hedging the probabilities at 16 to 1
again make that 24 to 1
yes
> > we get a las vegas betting line & final word at
> > 18 point 81552 inches north of the 1909 disk center
& so make this 18 point 82696 inches
> >
> >
> > thanx for your patience
> > & please add on or bust anything you can
& thanx for your first rate scrutiny as well
but my lingering question is
in this analysis
just because a digit comes up 0 or 5
does that in itself establish that it is therefore only a
demicentisec rather than a true millisec that only looks like it
might be a demicentisec
do you see what i mean
or isnt there actually a distinct probability of having a millisec &
another distinct probability of having a demicentisec in the case
of every 0 & 5 that occurs
as well as the 8 other distinct exclusively millisec probabilities
in the cases of the remaining 8 digits
so unless you can correct or improve me again
i would be inclined to consider this overall situation as not just a
2 in 10 chance times another 2 in 10 chance
but perhaps more like a 2 in 12 chance times a 2 in 12 chance
or maybe even a 2 in 20 chance times a 2 in 20 chance
or some other value
i dont know
for i dont know how to evaluate the relative likelihood of each of
these 2 distinctively different types of zeros & fives occurring in
reality
or is all this just a nevada mirage
with no likelihood at all other than the
2 in 10
times
2 in 10
you have already identified
meaning
if a digit comes up either 0 or 5 it is a suspected demicentisec
& if it comes up anything else it is not a suspected demicentisec
so we have only either a net 4 in 100 or a net 96 in 100 chance
for the series of 2 events we are analyzing
& end of story
but in fact which of these is the correct analysis & why