作者ntnulcy (要活就要Don't)
看板Statistics
標題[問題] 一題機率
時間Wed Jul 25 00:08:54 2007
At a grocery stone, eggs come in cartons that hold a dozen eggs. Experience
indicates that 78.5% of the cartons have no broken eggs, 19.2% have one
broken eggs, 2.2% have two broken eggs, 0.1% have three broken eggs, and
that the percentage of cartons with four or more broken eggs is negligible.
An egg selected at random from a carton is found to be broken. What is
the probability that this egg is the only broken one in the carton?
我的想法是......
P(A1):沒有蛋破掉的機率:0.785
P(A2):一個蛋破掉的機率:0.192
P(A3):兩個蛋破掉的機率:0.022
P(A4):三個蛋破掉的機率:0.001
P(A5):拿一個蛋出來的事件機率:1/12
P(A5 ∩ A2) P(A5) P(A2│A5)
所求 = P(A5│A2) = ─────── = ─────────
P(A2) P(A2)
1/12 ‧ 0.192
= ──────── = 1/12
0.192
不知道這樣做對不對?
懇請達人賜教 Orz
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