If x1, x2, x3 are three normally and independently distributed random
variables with means 7, 28, 6, and variances 4, 12, 4, respectively.
Suppose y = 2x1 + x2 + 3x3
(a) Find the distribution of y and its parameters.
(b) If a random sample of size 150 taken from the distribution of y, find
the probability of sample mean (X-Bar)lies between 59 and 61.
(c) Find the probability of sample mean (X-Bar) exceeds 62
不知道在这里发问适不适合
如果不适合 会自D
但是我怎么算都求不出来
而且这题目是老师自己出的
也没有所谓的解答
老师只是要我们自己想一想要怎么求解
真的很想要知道答案
拜托大家了...
谢谢