2011-09-21 15:07:39 来源: 互联网 责编:楷维留学指南
GMAT数学是GMAT考试的重要组成,GMAT数学概念是最基本的构成元素,我们通过学习GMAT数学概念,了解GMAT数学的最基本的出题规则,从而取得GMAT数学部分的了解熟悉。下面我们主要列出GMAT数学概念中描述统计(descriptive Statistics)部分词汇:
1.平均数(average or arithmetic mean)
2.中数(median)
To calculate the median of n numbers,first order the numbers from least to GREatest;if n is odd,the median is defined as the middle number,while if n is even,the median is defined as the average of the two middle numbers. For the DATa 6, 4, 7, 10, 4, the numbers, in order, are 4, 4, 6, 7, 10, and the median is 6, the middle number. For the numbers 4, 6, 6, 8, 9, 12, the median is (6+8 )/2 = 7. Note that the mean of these numbers is 7.5.
3.众数(mode):一组数中的众数是指出现频率最高的数。
例:the mode of 7,9,6,7,2,1 is 7。
4.值域(range):表明数的分布的量,其被定义为最大值减最小值的差。
例:the range of–1,7,27,27,36 is 36-(-1)= 37。
5.标准方差(standard deviation):
One of the most common measures of dispersion is the standard deviation. Generally speaking, the GREater the DATa are spread away from the mean, the GREater the standard deviation. The standard deviation of n numbers can be calculated as follows:
(1)find the arithmetic mean ;
(2)find the differences between the mean and each of the n numbers ;
(3)square each of the differences ;
(4)find the average of the squared differences ;
(5)take the nonnegative square root of this average.
Notice that the standard deviation depends on every DATa value, although it depends most on values that are fArthest from the mean. This is why a distribution with DATa grouped closely around the mean will have a smaller standard deviation than DATa spread far from the mean.
GMAT数学的基本概念,其实没有想象中那么复杂和混乱。可以根据归类的GMAT数学基本概念词汇,加以复习和记忆。值得注意的是,GMAT数学的基本概念,最忌讳的是死记硬背,最好采用理解式记忆法,基本概念就能轻松搞定。
免责声明:本站注明稿件来源为互联网或其他媒体的文、图或视频等稿件均为转载稿,本站转载出于非商业性的教育和科研之目的,并不意味着赞同其观点或证实其内容的真实性。如转载稿涉及版权等问题,请作者在两周内速来电或来函联系。
若文章来源为“楷维留学指南www.keywin.org”,转载时请务必注明出处。
[中国]中国人民解放军第三军医大学 Third Military Medical University
[楷维推荐指数]: 0 [所在州/地区]:重庆市 [所在城市]: [学费]:¥0/年
[日本]琉球大学 University of the Ryukyus
[楷维推荐指数]: 0 [所在州/地区]: [所在城市]: [学费]:¥0/年
[乌克兰]苏梅国立大学 Sumy State University
[楷维推荐指数]: 0 [所在州/地区]: [所在城市]: [学费]:¥0/年
[美国]杰纳西社区学院 Genesee Community College-SUNY
[楷维推荐指数]: 0 [所在州/地区]:纽约州 [所在城市]: [学费]:¥0/年
[西班牙]莱里达大学 Universitat de Lleida
[楷维推荐指数]: 0 [所在州/地区]:莱里达省 [所在城市]:莱里达 [学费]:¥0/年