首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
A list has 100 numbers, the expectation of the list is 10 and the standard deviation of the list is 4, then which pair of the in
A list has 100 numbers, the expectation of the list is 10 and the standard deviation of the list is 4, then which pair of the in
admin
2022-11-20
40
问题
A list has 100 numbers, the expectation of the list is 10 and the standard deviation of the list is 4, then which pair of the integers would make the standard deviation of the list decrease when the integers are put into the list?
选项
A、0, 20
B、0, 10
C、10, 10
D、-10, 0
E、-10, 10
答案
C
解析
大家已经非常熟悉标准方差,现在把两个数加人数列中,那么求方差时公式中的分母n就变大了,如果分子能够保持不变的话,方差一定变小。现在expectation=10,期望也就是平均值等于10,而C中的两个数(10,10)减去平均值以后都为0,因此对分子没有任何贡献,分子保持不变,那么方差变小,所以选择C。
转载请注明原文地址:https://kaotiyun.com/show/H4kO777K
本试题收录于:
GRE QUANTITATIVE题库GRE分类
0
GRE QUANTITATIVE
GRE
相关试题推荐
Thevitaminsnecessaryforahealthybodyarenormallysuppliedbyagoodmixeddiet(饮食),includingavarietyoffruitsandgre
WhatisthemajorfunctionofParagraph1?Accordingtothepassage,whetherTVisgoodornotdependson______.
ThephysicalproblemthatmanyadultAmericanshaveisthat______.Accordingtothearticle,given500adultAmericans,______
Witheverythingsheneeded,shewentoutoftheshop,withherhandsfullofshoppingbags.
Thespeed______is340meterspersecond.
AftersixmonthsoflivinginNewZealand,Irealizedonething.Despitemy【C1】______forgreatercontactwithlocalstudents,un
Ifathree-digitnumberisselectedatrandomfromtheintegers100to999,inclusive,whatistheprobabilitythatthefirstdi
Thereare8ballsinabox,2ofthemarered,4ofthemarewhite,2ofthemareblue.If2ballsaretobesimultaneouslyand
FRUSTRATE:
Notwishingtoincurthedisapprovalofherteachers,whoweregenerally(i)______,Helenwas(ii)______attemptingradicalnewa
随机试题
函数z=x3+y3一6xy的驻点为()
异烟肼易引起的不良反应是庆大霉素最严重的不良反应是
多媒体计算机的硬件必须包括( )。
E公司只产销一种甲产品,甲产品只消耗乙材料。2012年第4季度按定期预算法编制2013年的企业预算,部分预算资料如下:资料一:乙材料2013年年初的预计结存量为2000千克,各季度末乙材料的预计结存量数据如表1所示:每季度乙材料的购货款于当季支付40
你和另外一个同志一起做一件事,你发现有更好的办法但是需要格外做很多工作,你怎么做?
新形势下,中国共产党将长期面临的考验包括()。
对于分量视频、复合视频和S-video,以下说法不正确的是(32)。
Idon’tthinkthereisanythingwrongwithyourblood.Thekeytoyourproblemisthatlongnapafterdinner.Ifyoudidn’tsl
CivilizationBeforeabout3500BC,therewerecultures,butnotcivilizations.Prehistoricmenandwomencreatedsocieties,cons
Wal-Mart[A]Wal-Martismorethanjusttheworld’slargestretailer.Itisaneconomicforce,aculturalphenomenonandalightn
最新回复
(
0
)