统计学 R软件里pbinom的问题sum(dbinom(1:30,50,0.05))=0.923055为什么pbinom(30,50,0.05)=1,不是应该等于0.923055吗

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统计学 R软件里pbinom的问题sum(dbinom(1:30,50,0.05))=0.923055为什么pbinom(30,50,0.05)=1,不是应该等于0.923055吗
统计学 R软件里pbinom的问题
sum(dbinom(1:30,50,0.05))=0.923055
为什么pbinom(30,50,0.05)=1,不是应该等于0.923055吗

统计学 R软件里pbinom的问题sum(dbinom(1:30,50,0.05))=0.923055为什么pbinom(30,50,0.05)=1,不是应该等于0.923055吗
你的求和是从1开始的,而pbinom给的是从0开始的:
sum(dbinom(0:30,50,0.05))=1
另外,这个1也是为了显示舍入后的数字:
> sum(dbinom(0:30,50,0.05))-1
[1] -1.110223e-16