「Odds in statistics and Odds in a horse race」の版間の差分

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!style="width:50px"|Horses
 
!style="width:50px"|Horses
 
!style="width:80px"|Bettors
 
!style="width:80px"|Bettors
!style="width:200px"|If the horse wins, $20 are redistributed...
+
!style="width:150px"|If the horse wins,  
 +
!style="width:150px"|$20 are redistributed...
 
|-
 
|-
 
|style="text-align:center"|A
 
|style="text-align:center"|A
 
|10 bettors
 
|10 bettors
|$20 into 10 bettors; $20 ÷ 10 = $2
+
|$20 into 10 bettors
 +
|$20 ÷ 10 = $2
 
|-
 
|-
 
|style="text-align:center"|B
 
|style="text-align:center"|B
 
|5 bettors
 
|5 bettors
|$20 into 5 bettors; $20 ÷ 5 = $4
+
|$20 into 5 bettors
 +
|$20 ÷ 5 = $4
 
|-
 
|-
 
|style="text-align:center"|C
 
|style="text-align:center"|C
 
|3 bettors
 
|3 bettors
|$20 into 3 bettors; $20 ÷ 3 = $6.66...
+
|$20 into 3 bettors
 +
|$20 ÷ 3 = $6.66...
 
|-
 
|-
 
|style="text-align:center"|D
 
|style="text-align:center"|D
 
|2 bettors
 
|2 bettors
|$20 into 2 bettors; $20 ÷ 2 = $10
+
|$20 into 2 bettors
 +
|$20 ÷ 2 = $10
 
|-
 
|-
 
|style="text-align:center"|E
 
|style="text-align:center"|E
 
|1 bettor
 
|1 bettor
|$20 into 1 bettor; $20 ÷ 1 = $20
+
|$20 into 1 bettor
 +
|$20 ÷ 1 = $20
 
|}
 
|}

2022年11月6日 (日) 23:39時点における版

Definition of Odds in statistics

[math]\displaystyle{ Odds=\frac{probability\ that\ the\ outcome\ occurs}{probability\ that\ the\ outcome\ does\ not\ occur} }[/math]

Example of a horse rase

Assumption

In order to simplify, the bookmaker in the following scenario does not charge any betting fees

A race that 5 horses start and 10 bettors bet

Here is a horse race that 5 horses start and 20 people — 20 bettors — bet each of 5 horses.

Names of horses are A, B, C, D and E.

Horses
A
B
C
D
E

Each bettor bets $1 for one horse. All bet money are pooled ($20 pooled in total) and will be redistributed for bettors who bet a winning horse.

Now each all bettors bet as following:

Horses Bettors
A 10 bettors
B 5 bettors
C 3 bettors
D 2 bettors
E 1 bettor

Results

If each horse wins, pooled $20 are redistributed as following:

Horses Bettors If the horse wins, $20 are redistributed...
A 10 bettors $20 into 10 bettors $20 ÷ 10 = $2
B 5 bettors $20 into 5 bettors $20 ÷ 5 = $4
C 3 bettors $20 into 3 bettors $20 ÷ 3 = $6.66...
D 2 bettors $20 into 2 bettors $20 ÷ 2 = $10
E 1 bettor $20 into 1 bettor $20 ÷ 1 = $20