GMAT數(shù)學(xué)備考常見(jiàn)的幾個(gè)概念.

數(shù)學(xué)是GMAT考試中容易拿下的部分，但是GMAT數(shù)學(xué)我們知道對(duì)基礎(chǔ)知識(shí)的要求是比較高的。我們?cè)谧鲱}的時(shí)候常常會(huì)碰到很多概念，澳際小編給大家分享一些數(shù)學(xué)的概念，GMAT入門(mén)的考生要記得背誦：

　　下面我們主要列出GMAT數(shù)學(xué)概念中描述統(tǒng)計(jì)(descriptive statistics)部分詞匯：

　　1.平均數(shù)(average or arithmetic mean)

　　2.中數(shù)(median)

　　To calculate the median of n numbers，first order the numbers from least to greatest;if n is odd，the median is dined as the middle number，while if n is even，the median is dined 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.眾數(shù)(mode)：一組數(shù)中的眾數(shù)是指出現(xiàn)頻率最高的數(shù)。

　　例：the mode of 7，9，6，7，2，1 is 7。

　　4.值域(range)：表明數(shù)的分布的量，其被定義為最大值減最小值的差。

　　例：the range of–1，7，27，27，36 is 36-(-1)= 37。

　　5.標(biāo)準(zhǔn)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.

　　以上就是小編整理的GMAT考試數(shù)學(xué)部分常見(jiàn)的幾個(gè)概念，GMAT數(shù)學(xué)對(duì)于考生的基礎(chǔ)知識(shí)要求是比較高的。所以考生們?cè)趶?fù)習(xí)的時(shí)候要多多注意，GMAT入門(mén)的考生復(fù)習(xí)數(shù)學(xué)先從背誦基礎(chǔ)知識(shí)開(kāi)始做起吧。