Probabiltiy of fur getting accepted in 'n' trials

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Aritos
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Probabiltiy of fur getting accepted in 'n' trials

Post by Aritos »

I'm sharing some calculations which I did out of curiosity.

There is a 1 in 30 chance that Agostine will accept the White Fur for both the Winter Gloves and the Fur Boots.

If 'n' furs are submitted then probability of at least one of them getting accepted is 1 - (29/30)^n.

Odds will be in your favor at:
1 - (29/30)^n > 0.5
=> n > 20.4459
If u submit 20.4459 furs then odds will be like tossing a coin.

If u submit 30 furs then probability that at least 1 of them gets accepted, i.e. probability that not all of them get rejected is:
1 - (29/30)^30
=0.63833848653

White Furs are dropped by Fluffy at 8%. If 'x' fluffies are killed then for:
(1 - (0.08/30) )^x = 0.5
=> x = 259.583
Killing 259.583 fluffies for the gloves is like tossing a coin, in terms of probability.
Last edited by Aritos on 06 May 2014, 10:25, edited 2 times in total.
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wushin
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Re: Probabiltiy of fur getting accepted in 'n' trials

Post by wushin »

I believe the one that always gets people is the drop rate of Souls and the graveyard quest on 027-2.
After that it's diseased heart drop rate.

I do find this interesting though.
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Re: Probabiltiy of fur getting accepted in 'n' trials

Post by Cassy »

wushin wrote:I believe the one that always gets people is the drop rate of Souls and the graveyard quest on 027-2.
After that it's diseased heart drop rate.
And the Forest Bow Quest for new players.
If seen quite a couple of people complaining about it already because it took them far more than 20 Raw Logs (I heard two times about >100 Raw Logs).
I even wrote this line in the wiki to at least lower the frustration a bit for them:
This makes this quest sometimes harder than it looks like, but even though Log Heads are easy to kill and therefore the recommended level for this quest is just 20, the reward, the Forest Bow, is currently the best bow in the game until level 90.
Main characters:
Lv.94 - Cassy - speedarcher on dark path, bunny-wannabe, would like to ride on a Mouboo once...
Lv.95 - Biqcassy - mage on light path, addicted to her Fluffy Hat, love-hates Fallens, really misses Confused Tree...
Lv.70 - Simca. - dreams of becoming a speedarcher on light path, still has a lot to learn...

Personal development overview | priorities | wiki to-do | wiki profile incl. other characters

[20:24:59] <Cassy> debug npc in crypts!
[20:25:02] <Cassy> just a joke...
[20:25:08] <wushin> DONT DO THAT
[20:25:10] <o11c> !slap Cassy
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Re: Probabiltiy of fur getting accepted in 'n' trials

Post by Aritos »

I'm writing the following for future readers, you both may already be knowing the following.

If chance of success (like an item getting accepted or monster dropping the item) is 1/x or p%, then number of trials needed to make odds same as tossing a coin is:

log base (x-1)/x of 0.5

In terms of p percentage it's:

log base (1-p%) of 0.5

It's log base (chance of failure) of 0.5

There's a 2% chance that Jack O Soul gets accepted. You can input on www.wolframalpha.com :
log base (1-2%) 0.5

If we do that there's 1 in 50 chance of Jack O Soul getting accepted then:
log base 49/50 0.5

Answer to both is 34.3096 .

There's a 1.2% chance that a zombie will drop diseased heart:
log base (1-1.2%) 0.5 = 57.415 .

Forest Bow Quest: log base 19/20 0.5 = 13.5134 .
It took me 3 or 4 logs to complete the quest :)
If sm1 doesn't succeed in 100 logs then as 100/13.5134 = 7.4 means he tossed coin approx. 7 times and it never came out to be head.
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Re: Probabiltiy of fur getting accepted in 'n' trials

Post by Cassy »

Nice :D
I'm horribly bad in math so I have can only look at the results.... but I like statistics.
Aritos wrote:It took me 3 or 4 logs to complete the quest :)
The second time I did this quest it took me ~60 Raw Logs, but the last time I needed just one... yeah, just 1 *was very lucky*
Main characters:
Lv.94 - Cassy - speedarcher on dark path, bunny-wannabe, would like to ride on a Mouboo once...
Lv.95 - Biqcassy - mage on light path, addicted to her Fluffy Hat, love-hates Fallens, really misses Confused Tree...
Lv.70 - Simca. - dreams of becoming a speedarcher on light path, still has a lot to learn...

Personal development overview | priorities | wiki to-do | wiki profile incl. other characters

[20:24:59] <Cassy> debug npc in crypts!
[20:25:02] <Cassy> just a joke...
[20:25:08] <wushin> DONT DO THAT
[20:25:10] <o11c> !slap Cassy
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Re: Probabiltiy of fur getting accepted in 'n' trials

Post by wushin »

The rate on Souls is altered by the rate at which someone can kill a Jack'O.
being a rarer spawn and harder to kill it makes the drop more rare based on difficulty.

So the other factor is at what level can someone obtain X and at what rate.

As if I can only kill a Jack'O every X minutes vs. Logheads which one can kill relatively fast compared to that.
The secret to getting all the important stuff done is doing nothing.
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Re: Probabiltiy of fur getting accepted in 'n' trials

Post by Aritos »

wushin wrote:The rate on Souls is altered by the rate at which someone can kill a Jack'O.
being a rarer spawn and harder to kill it makes the drop more rare based on difficulty.

So the other factor is at what level can someone obtain X and at what rate.

As if I can only kill a Jack'O every X minutes vs. Logheads which one can kill relatively fast compared to that.
Ya, one can measure the avg. time it's taking him to kill a particular monster.

By the way, like I calculated for Fluffy:

A Log Head drops a log at chance of 20%. Probability that a Log Head killing gets converted to Forest Bow is:
Probability of Log Head dropping log * Probability of log getting accepted
= (20/100) * (1/20)
= 1/100

As log base 99/100 0.5 = 68.9676, one needs to kill 69 Log Heads to turn the odds (of getting a Forest Bow) to more than 50%.
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