数学是GMAT考试中容易拿下的部分，但是GMAT数学我们知道对基础知识的要求是比较高的。我们在做题的时候常常会碰到很多概念，小站教育给大家分享一些数学的概念，GMAT入门的考生要记得背诵。
GMAT数学概念中描述统计部分词汇：
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.
以上就是我们小站教育为各位考生整理的关于备考GMAT数学常见概念介绍，希望考生积极做好备考工作，及时调整好状态，争取在GMAT数学考试中取得理想的成绩！
