OG12数学关于中位数算法求助！

witty1 · 发表于 2011-4-30 20:56:52

1.A certain bookcase has 2 shelves of books. On the upper shelf, the book with the greatest number of pages has 400 pages. ON the lower shelf, the book with the least number of pages has 475 pages. What is the median number of pages for all of the books on the 2 shelves.
1. There are 25 books on upper shelf.
2. There are 24 books on lower shelf.
C

2.What is the median number of employees assigned per project for the projects at Company Z?

(1) 25 percent of the projects at Company Z have 4 or more employees assigned to each project.
(2) 35 percent of the projects at Company Z have 2 or fewer employees assigned to each project.
C

witty1 · 发表于 2011-4-30 21:07:19

please help!

小唯唯 · 发表于 2011-4-30 23:52:32

1 只能是两个条件一起用才能做呀~ 只知道上层的书的数量或只知道下面的都不行。转化：上面25个数，且最大的一个是400，下面24个数，最小一个是475，那么中间那个就是第25个数，即400

2 我当时也错了……哎……其实想一下就懂了。小于等于2的是35% 大于等于4的是25%，那么剩下的40%全都等于3（因为人数必须为整数）则就想：前面35个2 中间40个3 后面25个4 那中位数是在低50和51求平均，即两个三加起来在除以二就是3

OG12数学关于中位数算法求助！

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