首页
登录
职称英语
A research scientist wants to study a certain attribute of dogs. It is estimated
A research scientist wants to study a certain attribute of dogs. It is estimated
游客
2025-02-24
40
管理
问题
A research scientist wants to study a certain attribute of dogs. It is estimated that approximately 5 percent of all dogs have this attribute. If the scientist wants to study a sample of N dogs having the attribute, approximately how many dogs should be screened in order to obtain the desired sample size?
选项
A、N/5.
B、5N.
C、20N.
D、105N.
E、120N.
答案
C
解析
一科学家想研究狗的某种特性。据估计约有5%的狗具有这种特性。若这位科学家想把N只具有这种特性的狗作为一个样本来研究,那么为了得到期望的样本大小,大约需要筛选多少条狗?
解:本题的正确答案为(C)。设需筛选x条狗,则由题意可得:x×5%=N → x=20N
转载请注明原文地址:http://tihaiku.com/zcyy/3971370.html
相关试题推荐
Acertainrectanglehasperimeter54.Iftheratioofthelengthoftherectangl
Thecost,indollars,foranappliancerepairatacertaincompanyis1.2p+20h
Whenacertainnumberisdividedby7,theremainderis0.Iftheremainderisn
When2/5ofacertainnumberisaddedtothenumberandthissumissubtractedf
Theoddsthatacertaineventwilloccuristheratiooftheprobabilitythatth
Whatisthecost,incents,ofusingacertainfaxmachinetosendnpagesofa
Ifacertaincompanypurchaseditscomputerterminalsforatotalof$540,400an
Onacertainnumberline,if-7isadistance4fromnand7isadistanceof18
Acertainintegernisamultipleofboth5andMustnbeamultipleof15?15The
AcertainhighwayhasExits1,2,3,and4inthatorder.Whichofthefollowing
随机试题
Mostpeoplemadeforforthemovietheaterstoescaperealityforafewhours.A、
Doyouwanttoliveforever?Bytheyear2050,youmightactuallygetyourw
Mary:Yourlittleboyhasdoneagoodjobatschool.Eva:______A、Yes,youare
钙通道阻滞药作用包括()A.心脏负性变时作用 B.心脏负性变力作用 C.
当地时间2016年11月9日,美国()唐纳德·特朗普总统候选人当选美国第五十八届
关于铁代谢的叙述错误的是A:人体内铁可分为功能铁和储存铁B:铁蛋白中的铁是可立
骨髓形态学表现相关疾病: 霍奇金淋巴瘤A.骨髓增生极度低下 B.大量原始细胞
2003年6月份,“国房景气指数”达到107.04,比5月份上升0.76点,比去
劳动关系的运行主要包括()的内容。A.组织机构与相互关系 B.关系处理的规则
水闸中能起防冲消能作用的构造有()。A.上游护坡 B.护坦 C.下游翼
最新回复
(
0
)