题目
If the average rate of HFLS operational loss events instead is 20 per workweek (20 every five days), if we assume a Poisson distribution, what is the probability on a given single day that between four and six HFLS losses will occur, inclusive?
选项
A.35.6%
B.45.6%
C.55.6%
D.65.6%
答案
B
解析
The rate is 20/5 or 4 per day. λ is 4.P(X=4)= 19.537%,P(X=5) = 15.629%,P(X=6) = 10.42%.P(X=4) ＋ P(X=5) ＋ P(X=6) = 19.537% ＋ 15.629% ＋ 10.42% = 45.586% 发生频率是每5天20次或者是每天4次。因此λ 是4。 PX=4= 19.537%, P(X=5) = 15.629%, P(X=6) = 10.42%. P(X=4)＋P(X=5) ＋P(X=6) = 19.537%＋ 15.629% ＋ 10.42% = 45.586%