Question

一道英文数学题 帮忙解答一下 在线等

the weights of egge produced on a farm are normally distributed with a mean of 1.4 ounces and a standard deviation of 0.4 ounces
1. what percent of the eggs weight at least 1 ounce？
2.how many of 1200 eggs are withiin 2 standard deviations of the mean？
3.to be a graded extra large，an egg must weight at least 2.2 ounces. what is the probability that an egg from this form will be graded extra large？

Answer 1

一个牧场上所产鸡蛋的重量服从均值为1.4盎司标准差为0.4盎司的正态分布
1.至少重1盎司的鸡蛋占多少比率？
2.1200个鸡蛋中有多少个是在上述均值和两倍标准差的区域内的？
3.一个鸡蛋必须重至少2.2盎司（即大于等于）才能被分级为特大号，请问这个牧场产出特大号鸡蛋的概率？

题目意思如上所述，你自己去翻翻概率论的教科书就会做了，套套公式的题目而已，输入数学式子和符号比较麻烦，楼主自己动手做做吧~

Answer 2

少了很资料啊

Answer 3

1、84.13%
2、0.6826×1200=819.12≈819个
3、0.0228