一道统计学的题,要用到λ,麻烦会的大侠给出详细答案.

题目

一道统计学的题,要用到λ,麻烦会的大侠给出详细答案.
A Hospital Emergency Department has,on average,30 new patients arrive each hour.They plan human resources in ten minute intervals and want to ensure that they have sufficient doctors and nurses to cover most scenarios.
Required:
1.For a ten minute interval,what is the probability that exactly five patients arrive in the Emergency Department?
2.For a ten minute interval,what is the probability that three or fewer patients arrive in the Emergency Department?
3.For a ten minute interval,what is the probability that four or more patients arrive at the Emergency Department?

答案

你的题目需要用到泊松分布的概率函数（Poisson probability distribution）公式.平均来说,每10分钟就有5个病人到急诊室（每小时30个）,因此λ=5.以下我使用Excel软件进行计算,你将我的式子复制、粘贴到Excel的公式编...