Need Statistical Help!

[sambal]

Originally Posted by Estu [You must be logged in to view images. Log in or Register.]

So in the previous case, each one has a 50% chance to drop and 75% of the time we get at least one bone chip, but the expected number of bone chips is 0*25% + 1*50% + 2*25% = 1, so the wiki would show a "likelihood" of 100%. These cases would, I'm assuming, complicate the confidence intervals, though most pieces of loot that drop can only drop once, so it's more straightforward.

Any stats nerds wanna help me out? Thanks!

I don't think you're 100% correct here.

The skeleton is drawing from the possibility of dropping two bones, each with the probability of 50%. This is the way almost every video game works, which does wind up yielding a normal distribution. It's much easier for the server to compute these straightforward loot tables, and appear to be convoluted to the player.

p_Bone_A = 0.5
p_Bone_B = 0.5

Probability that bone_A does not drop, P(A'):........................... 0.5 (no bone_A, irrespective of bone_B)
Probability that bone_B does not drop, P(B'):........................... 0.5 (no bone_B, irrespective of bone_A)
Probability that bone_A or bone_B drops, but not both:............. 0.5 (one bone)
Probability that bone_A and bone_B both drops, P(A∩B):............ 0.25 (two bones)
Probability that bone_A and/or bone_B drops, P(A∪B):............... 0.75 (one or two bones)
Probability that neither bone_A or bone_B drops, P(A'∩B'):.......... 0.25 (zero bones)