首页
登录
职称英语
A list has 100 numbers, the expectation of the list is 10 and the standard devia
A list has 100 numbers, the expectation of the list is 10 and the standard devia
游客
2024-01-12
47
管理
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://www.tihaiku.com/zcyy/3354754.html
相关试题推荐
Upsetbytherecentdownturninproductionnumbersduringthefirsthalfofthe
ALaborDepartmentstudystatesthatthenumbersofwomenemployedoutsidetheh
Althoughnumbersofanimalsinagivenregionmayfluctuatefromyeartoyea
Althoughnumbersofanimalsinagivenregionmayfluctuatefromyeartoyea
Althoughnumbersofanimalsinagivenregionmayfluctuatefromyeartoyea
Althoughnumbersofanimalsinagivenregionmayfluctuatefromyeartoyea
Insettingenvironmentalstandardsforindustryandotherstomeet,itisinadvi
Ifn=pqr,wherep,q,andrarethreedifferentpositiveprimenumbers,howma
Whichofthefollowingnumbersisbothafactorof48andamultipleof6?A、2B
Forallrealnumberspandr,p◇r=pr-p+r.ColumnAColumnB
随机试题
[originaltext]Whatdoyouthinkofourmanager?[/originaltext][originaltext]He
Therearevariouswaysinwhichindividualeconomicunitscaninteractwith
Manstillhasalottolearnaboutthemostpowerfulandcomplexpartofhis
AfterWorldWarII,whenalargecollectionofImpressionistpaintingswasm
燃气管道试验介质宜采用( )。A.水 B.燃气 C.空气 D.液压油
许多工业企业生产中生成的粉尘都具有爆炸性。下列具有爆炸性的粉尘是()。A.铝粉
2011年某省接待过夜游客总量再次实现突破,达到3001.34万人次,同比增长
变压器蝶阀应有开关位置指示标识。
根据相关规定,下列不应认定为工伤或视同工伤的是()。A.某女士在下班途中遭遇车祸
集体谈判双方坚持点的确定,主要取决于()等因素。 A.宏观经济状况B
最新回复
(
0
)