無論是參加過或者正準備參加GMAT數學考試的考生，都發現了GMAT數學基本概念名目種類繁多，記憶起來困難重重。其實，他們沒有將GMAT數學的所有基本概念歸類，造成記憶出現混亂。GMAT數學的基本概念真的有那么多嗎?我們應該如何把握?且看本文給你曬曬。

　　描述統計

　　1.平均數

　　2.中數

　　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 /2 = 7. Note that the mean of these numbers is 7.5.

　　3.眾數：一組數中的眾數是指出現頻率最高的數。

　　例：the mode of 7，9，6，7，2，1 is 7。

　　4.值域：表明數的分布的量，其被定義為最大值減最小值的差。

　　例：the range of1，7，27，27，36 is 36-= 37。

　　5.標準方差：

　　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:

　　find the arithmetic mean ;

　　find the differences between the mean and each of the n numbers ;

　　square each of the differences ;

　　find the average of the squared differences ;

　　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數學的基本概念，如果考生加以歸類，會感覺沒有想象中那么復雜和混亂。考生可以根據歸類的GMAT數學基本概念，加以復習和記憶。還要提醒考生的是，GMAT數學的基本概念，最忌諱的是死記硬背，考生最好采用理解式記憶法，GMAT數學基本概念就能輕松搞定。

　　無論是參加過或者正準備參加GMAT數學考試的考生，都發現了GMAT數學基本概念名目種類繁多，記憶起來困難重重。其實，他們沒有將GMAT數學的所有基本概念歸類，造成記憶出現混亂。GMAT數學的基本概念真的有那么多嗎?我們應該如何把握?且看本文給你曬曬。

　　描述統計

　　1.平均數

　　2.中數

　　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 /2 = 7. Note that the mean of these numbers is 7.5.

　　3.眾數：一組數中的眾數是指出現頻率最高的數。

　　例：the mode of 7，9，6，7，2，1 is 7。

　　4.值域：表明數的分布的量，其被定義為最大值減最小值的差。

　　例：the range of1，7，27，27，36 is 36-= 37。

　　5.標準方差：

　　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:

　　find the arithmetic mean ;

　　find the differences between the mean and each of the n numbers ;

　　square each of the differences ;

　　find the average of the squared differences ;

　　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數學的基本概念，如果考生加以歸類，會感覺沒有想象中那么復雜和混亂。考生可以根據歸類的GMAT數學基本概念，加以復習和記憶。還要提醒考生的是，GMAT數學的基本概念，最忌諱的是死記硬背，考生最好采用理解式記憶法，GMAT數學基本概念就能輕松搞定。