Need Statistic/Math Help

SSBrew - 728
Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum

Help Support Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
TxBrew

TxBrew

Administrator
Staff member
Admin
Joined
Feb 10, 2004
Messages
9,308
Reaction score
2,114
Lets say I have 375 users that enter a giveaway and I need to pick a winner at random that everyone can verify is true.

Here is my theory on how to do this and I need to know if there are any flaws in it:

Texas Cash Five gets pulled everyday so the day after the giveaway ends the lotto will be drawn.

I can put everyone into a X amout of groups with X amount of users. I will put users in the groups randomly and post them prior to the lotto.

The numbers today were 27 37 9 34 15.

So lets say we have 15 user groups then the first pull between 1 and 15 picks the user group. Now we have which user group we are going to use. In this case group 9 wins.

Now lets say in each user group we have 25 users. Excluding the ball we used to select the user group the next ball between 1-26 selects the user. The 9th user is now the 10th user because 9 can't be drawn again. So we move everyone past 8 up; 16 is now 17, 17 is now 18, so forth.

The next ball between 1-26 is 15 so the winner is Group 9 Member 15.
 
You won't know how many groups to put them in until after the lottery. Unless you want to take your chances of low enough numbers being drawn. If you divide everyone up into groups and users first, there might be a chance that the numbers drawn do not coencide with your lists. If you do it after the lottery, then there exists the possibility that it wouldn't be "at random".

loop
 
You just gave me a headache. It's 5am here and I'm awake with a sore foot and leg (on going pain thing form a work injury).

I think I'll give this shot during normal waking hours....

BTW what are the number ranges for the texas cash draw?
 
Can't you just run a random number generator and pick a random number between 1 and 375? :confused:
 
Assuming the Cash Five is picking five numbers between 1 & 99, you can just split the people into five groups using sign-up order (1,6,11 ... in group One, etc.) Then the prize goes to whomever matches the drawn number in each group. If no one in the group matches (say the number was 96 and there are only 78 people in the group), use the next day's group number.
 
TxBrew said:
Lets say I have 375 users that enter a giveaway and I need to pick a winner at random that everyone can verify is true.

Here is my theory on how to do this and I need to know if there are any flaws in it:

Texas Cash Five gets pulled everyday so the day after the giveaway ends the lotto will be drawn.

I can put everyone into a X amout of groups with X amount of users. I will put users in the groups randomly and post them prior to the lotto.

The numbers today were 27 37 9 34 15.

So lets say we have 15 user groups then the first pull between 1 and 15 picks the user group. Now we have which user group we are going to use. In this case group 9 wins.

Now lets say in each user group we have 25 users. Excluding the ball we used to select the user group the next ball between 1-26 selects the user. The 9th user is now the 10th user because 9 can't be drawn again. So we move everyone past 8 up; 16 is now 17, 17 is now 18, so forth.

The next ball between 1-26 is 15 so the winner is Group 9 Member 15.
Click to expand...

I think the problem here is the possibility that no one would be selected if you made groups before knowing the day's numbers and if you made the groups after the numbers were selected, then it wouldn't be random.


David_42 said:
Assuming the Cash Five is picking five numbers between 1 & 99, you can just split the people into five groups using sign-up order (1,6,11 ... in group One, etc.) Then the prize goes to whomever matches the drawn number in each group. If no one in the group matches (say the number was 96 and there are only 78 people in the group), use the next day's group number.
Click to expand...

I don't think this is random because it is based on the order in which people sign up.

I don't have an idea on how to do this yet, but I'll post again if I think of anything.
 
Ok, I've got an idea now.

Take twelve ten sided dice, with the numbers 0 thru 9 on the sides. Roll each die and record the number. You should now have a 12 digit number.

Assign each person a number.

12 digit Number % 375 = winner

% = modulus or remainder.
 
The only thing I see wrong is that in your scenario the winner should have been Group 9 Member 14, due to numbers past 9 needing to be shifted after the 9 ball was drawn (if I'm understanding your system correctly).
 
TxBrew said:
Lets say I have 375 users that enter a giveaway and I need to pick a winner at random that everyone can verify is true.

Here is my theory on how to do this and I need to know if there are any flaws in it:

Texas Cash Five gets pulled everyday so the day after the giveaway ends the lotto will be drawn.

I can put everyone into a X amout of groups with X amount of users. I will put users in the groups randomly and post them prior to the lotto.

The numbers today were 27 37 9 34 15.

So lets say we have 15 user groups then the first pull between 1 and 15 picks the user group. Now we have which user group we are going to use. In this case group 9 wins.

Now lets say in each user group we have 25 users. Excluding the ball we used to select the user group the next ball between 1-26 selects the user. The 9th user is now the 10th user because 9 can't be drawn again. So we move everyone past 8 up; 16 is now 17, 17 is now 18, so forth.

The next ball between 1-26 is 15 so the winner is Group 9 Member 15.
Click to expand...

dude, my head hurts.....:drunk:
 
LupusUmbrus said:
The only thing I see wrong is that in your scenario the winner should have been Group 9 Member 14, due to numbers past 9 needing to be shifted after the 9 ball was drawn (if I'm understanding your system correctly).
Click to expand...

But using my method if the people entering know beforehand then 14 is not the winner because I spelled out how it will be done.

The flaw I see if I use 15 groups of 25 people I have to get 1 number under 16 and another under 26. If that doesn't happen then we wait till the next day drawing. Looking at the # from all the past drawings it doesn't happen often.

Random number generator is the quick way to do it but I want a way that is verifable by everyone and no one can call BS or say "this was rigged".

I think using my method is flawless in it being totally random but math is not my forte esp. stats so thought someone might see a bigger flaw.
 
orfy said:
TX brew,

I think we all trust you to do the draw and annouce the winner.
No verification required here.
Click to expand...



I'm with orfy. If this were for our own brewpub, then you might want to reconsider. But for a set of etched glasses, we trust you. :)

loop
 
Tx, I'm going to send you a check in the mail for my gold membership. You can trust that I trust you. I think that nobody would complain about the results.

Of course, you could just pick a number between 1 and 10,000, and choose the winner as closest to the number.
 

Similar threads

inkbird
GIVEAWAY TIME - INKBIRD Wireless Meat Thermometer INT-11P-B
2
Replies
50
Views
2K
CKuhns
CKuhns
inkbird
GIVEAWAY for INKBIRD NEWEST Upgrade Wi-Fi Bluetooth BBQ Temperature Controller!
2
Replies
43
Views
2K
mbauer013
M
3 Dawg Night
FotHB XIX: Legal to Drink in Canada
2 3
Replies
86
Views
3K
3 Dawg Night
3 Dawg Night
T
FotHB XVIII: In Memory of @aharri1 [RIP]
2 3 4
Replies
132
Views
7K
RCope
RCope
Protos
Vintage Danish Beers Brewed With Fermentis Safbrew LA-01
Replies
4
Views
1K
Knox
K
Yakima 300

Latest posts

Back
Top