统计学,英文,

题目

统计学,英文,
A random variable X is given such that X ∼ N(82,126).
a.One of the different values of X is chosen at random.If this value can be
rounded to the nearest whole number,what is the probability that this whole
number is 84?
b.If we take five independent values of the variable X,find the probability that
not more than one of them is greater than 87.
c.If P(87< X < k) = 0.3,find the value of k.

答案

1.求的是P(84<x<85),首先你要知道cumulative distribution function怎么算,P(84<x<85)=F(85)-F(84)把μ=82和σ^2=126代入,有上面和下面分别是解析解和数值解2.第二题问的是五个独立变量X,至多一个大...