GRE数学:基本概念总结篇
<p> <span word="GRE">GRE</span>数学:基本概念总结篇</p><p> 一、数学基本概念</p><p> 1、<span word="mode">mode</span></p><p> 一堆数中出现频率最高的一个或几个数</p><p> <span word="e">e</span>.<span word="g">g</span>. <span word="mode">mode</span> <span word="of">of</span> 1,1,1,2,3,0,0,0,5 <span word="is">is</span> 1 <span word="and">and</span> 0</p><p> 2、<span word="range">range</span></p><p> 一堆数中最大和最小数之差</p><p> <span word="e">e</span>.<span word="g">g</span>. <span word="range">range</span> <span word="of">of</span> 1,1,2,3,5 <span word="is">is</span> 5-1=4</p><p> 3、<span word="mean">mean</span></p><p> <span word="arithmatic">arithmatic</span> <span word="mean">mean</span></p><p> <span word="geometric">geometric</span> <span word="mean">mean</span> <span word="n">n</span>个数之积的<span word="n">n</span>次方根</p><p> 4、<span word="median">median</span></p><p> 将一堆数排序之后，正中间的一个数，</p><p> 或者中间两个数的平均数</p><p> <span word="e">e</span>.<span word="g">g</span>. <span word="median">median</span> <span word="of">of</span> 1,7,4,9,2,2,2,2,2,5,8 <span word="is">is</span> 2</p><p> <span word="median">median</span> <span word="of">of</span> 1,7,4,9,2,5 <span word="is">is</span> /2=6</p><p> 5、<span word="standard">standard</span> <span word="error">error</span></p><p> 一堆数中，每个数与平均数的差的绝对值之和，除以这堆数的个数</p><p> <span word="e">e</span>.<span word="g">g</span>. <span word="standard">standard</span> <span word="error">error</span> <span word="of">of</span> 0,2,5,7,6 <span word="is">is</span>:</p><p> /5=2.4</p><p> 6、<span word="standard">standard</span> <span word="variation">variation</span></p><p> 一堆数中，每个数与平均数之差的平方之和，再除以<span word="n">n</span></p><p> <span word="e">e</span>.<span word="g">g</span>. <span word="standard">standard</span> <span word="variation">variation</span> <span word="of">of</span> 0,2,5,7,6 <span word="is">is</span>: <span word="s">s</span></p><p> _ 2 2 2 2 2_</p><p> |_ ++++_|/5=6.8</p><p> 7、<span word="standard">standard</span> <span word="deviation">deviation</span></p><p> 就是<span word="standard">standard</span> <span word="variation">variation</span>的平方根</p><p> 标准方差的公式：<span word="d">d</span>^2=/<span word="n">n</span></p><p> <span word="d">d</span> 为标准方差</p>
页:
[1]