2017年如何复习新GRE数学考试

　　俗话说：“工欲善其事必先利其器”。很多参加了新版GRE考试的同学都觉得数学有点难度，相信这其中的原因还是由于考生在新版GRE数学复习时没有把基础打牢。如果新版GRE数学基本考点都没有复习到，如何能拿到分数呢?所以说，想要新版GRE数学考好，复习的时候一定要把基本概念和重要考点都弄扎实。

　　今天针对新版GRE数学复习，小编给大家整理的是关于平均数的相关内容，这些概念在考试中一定会考到的。希望考生能再接再厉，取得一个好成绩，突破新版GRE数学难的困境。

　　新版GRE数学复习重要考点：AP

　　Average of n numbers of arithmetic proGREssion (AP) is the average of the smallest and the largest number of them. The average of m number can also be written as x + d(m-1)/2.

　　Example:

　　The average of all integers from 1 to 5 is (1+5)/2=3

　　The average of all odd numbers from 3 to 3135 is (3+3135)/2=1569

　　The average of all multiples of 7 from 14 to 126 is (14+126)/2=70

　　remember:

　　Make sure no number is missing in the middle.

　　With more numbers, average of an ascending AP increases.

　　With more numbers, average of a descending AP decreases.

　　AP:numbers from sum

　　given the sum s of m numbers of an AP with constant increment d, the numbers in the set can be calculated as follows:

　　the first number x = s/m - d(m-1)/2,and the n-th number is s/m + d(2n-m-1)/2.