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Weighted Mean
Posted by RADAR on September 23, 2016 at 9:43 pmCan someone help me with my math?
The North line of the Quarter is N 88å¡03’11Û W 1317.47′
The South line of the Quarter is N 87å¡50’19Û W 586.90′I’m looking for the direction of the east/west center-line of the Quarter, based on the weighted mean of the north and south line.
I’m reeeeealy close to the guy before me; I just want to make sure we’re not both wrong…:innocent:
TIA
Dougie
paul-in-pa replied 7 years, 11 months ago 18 Members · 39 Replies -
39 Replies
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RADAR, post: 392441, member: 413 wrote: Can someone help me with my math?
The North line of the Quarter is N 88å¡03’11Û W 1317.47′
The South line of the Quarter is N 87å¡50’19Û W 586.90′I’m looking for the direction of the east/west center-line of the Quarter, based on the weighted mean of the north and south line.
I’m reeeeealy close to the guy before me; I just want to make sure we’re not both wrong…:innocent:
TIA
Dougie
I don’t think I understand what you want…..but why is the south line of the quarter less than 600 feet?
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Tom Adams, post: 392447, member: 7285 wrote: I don’t think I understand what you want…..but why is the south line of the quarter less than 600 feet?
Lake?
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Tom Adams, post: 392447, member: 7285 wrote: I don’t think I understand what you want…..but why is the south line of the quarter less than 600 feet?
Puget Sound
I hope everyone has a great day; I know I will! -
The easy method that I was taught with CAD is to draw as many legs of a polyline as you want at as many varying lengths and bearings as you want. Then you inverse the beginning to the end of the polyline-the bearing that you get is a weighted mean.
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Ah – that sounds like the Grant Boundary adjustment method. See section 7-54 of the 2009 Manual.
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I think we need more info… ie, the distances between these lines. Then, they are weighted by their location…..
So, draw the figure, ie, both lines. then draw the lines on east and west ends. Then, connect those 2 lines via mid pnts.
Closer to the north, or south, affects them.
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Guy Townes, post: 392444, member: 11463 wrote: I get N 87å¡59’13” W
Me too…same answer.
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Nate The Surveyor, post: 392453, member: 291 wrote: I think we need more info… ie, the distances between these lines.
N 2å¡35’16Û E 2651.98′
I hope everyone has a great day; I know I will! -
Pretty confident on how I did the weighted mean. I did it with CAD. As far as Grant Boundary (someone correct me on f I’m wrong) my understanding is that if you take several legs (record) with angle points and, for example, you find monuments on each end of this polyline. You then take the polyline, place it on one of the found monuments, then rotate AND scale to the other monument. This in essence proportions all the legs while holding the record angles.
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RADAR, post: 392459, member: 413 wrote: N 2å¡35’16Û E 2651.98′
Is this the east line?
Im at the county fair.
Not much math from me tonite! -
Nate The Surveyor, post: 392464, member: 291 wrote: Is this the east line?
Im at the county fair.
Not much math from me tonite!The weighted mean bearing only requires the two (roughly) parallel lines, the distance between them is not relevant. It is used to get a centerline bearing on a fractional section where one of the relevant quarter corners was not set.
You simply traverse the first from point 1 to point 2, then the second from point 2 to point 3 then inverse point 1 to point three to get a weighted mean bearing.
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If the legal mid, is not at the math mid pt…
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Nate The Surveyor, post: 392464, member: 291 wrote: Im at the county fair.
we want pictures!
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Dave Karoly, post: 392467, member: 94 wrote: The weighted mean bearing only requires the two (roughly) parallel lines, the distance between them is not relevant. It is used to get a centerline bearing on a fractional section where one of the relevant quarter corners was not set.
You simply traverse the first from point 1 to point 2, then the second from point 2 to point 3 then inverse point 1 to point three to get a weighted mean bearing.
damn, never thought of that method, but it comes out right
(verified using the spread sheet with formulas I created from the manual instructions, but maybe it has errors [need more coffee])
good tip Dave, thanks -
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RADAR, post: 392441, member: 413 wrote: Can someone help me with my math?
The North line of the Quarter is N 88å¡03’11Û W 1317.47′
The South line of the Quarter is N 87å¡50’19Û W 586.90′I’m looking for the direction of the east/west center-line of the Quarter, based on the weighted mean of the north and south line.
I’m reeeeealy close to the guy before me; I just want to make sure we’re not both wrong…:innocent:
TIA
Dougie
Careful… You’re not just slapping math on the ground are you?
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