※ 引述《AAJJBurnett (叫我投手)》之铭言： : Let the random variable X be the number of days that a certain patient needs : to be in the hospital. Say X has the p.m.f. : 5-x : f(x)= ------- x=1,2,3,4. : 10 : If the patient is to receive from an insurance company 200(元) for each of : the first two days in the hospital and 100(元) for each day after the first : two days, what is the expected payment for the hospitalization? 我的想法是......... f(1)=4/10，住院1天领保险费200元 f(2)=3/10，住院2天........200+200元 f(3)=2/10，....3..........200+200+100元 f(4)=1/10，....4..........200+200+100+100元 所以保险公司要赔的钱期望值为： 4/10*200 + 3/10*400 + 2/10*500 + 1/10*600 = 360 -- 有错请指教.. --

※ 发信站: 批踢踢实业坊(ptt.cc) ◆ From: 123.205.238.93