A company is made up of 450 employees who work a total of 13,500 hours per week.If The number of weekly work hours per p
问题描述：
A company is made up of 450 employees who work a total of 13,500 hours per week.If The number of weekly work hours per person has a normal distribution and the standard deviation equals 7 hours,how many employees work more than 37 hours per week?
答
答案是72
平均值是:13500/450=30 因为标准差是7所以是均值加上一个标准差,这段距离在数学上是被证明过大概是34%,所以大于37小时的百分数大概是50%-34%=16% 即 16%*450=72人
PS：第一个标准差到第二个标准差之间大概是14%,我记得这两个数字OG的数学部分是有的,图像更加直观你可以去看看看过了。我没看过解析，我就是拿真题练下。20道里面就这道题目不会做。