作者Jordan23 (我正在浪費生命!!)
看板Statistics
標題Re: [問題] 求期望值
時間Thu Apr 13 00:19:02 2006
※ 引述《stonycindy (Esperanza)》之銘言：
: Q1: A store selling newspapers only orders n=4 of a certain newspaper because
: the manager does not get many calls for that publication. If the number of
: requests per day follows a Poisson distribution with mean three,
: (a) What is the excepted value of the number sold?
: Answer：2.681
1*P(X=1)+2*P(X=2)+3*P(X=3)+4*P(X>3), where X~Poi(3)
: Q2: An airline always overbooks, if possible. A particular plane has 95 seats
: on a flight in which a ticket sells for $300. The airline sells 100 such
: tickets for this flight.
: (a) If the airline must return the $300 price plus a penalty of $400 to
: each passenger that cannot get on the flight, what is the expected
: payout(penalty plus ticket refund) that the airline will pay?
: Answer:$ 598.56 using binomial, $ 613.90 using Poisson approximation
看不出來要對什麼做 approximation?
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◆ From: 61.224.74.127
1F：推 stonycindy:Q2. The probability of an individual not showing is 04/13 09:21
2F：→ stonycindy:0.05. 04/13 09:22