首页
登录
职称英语
For which of the following bird species is the standard deviation of the numbers
For which of the following bird species is the standard deviation of the numbers
游客
2024-01-12
17
管理
问题
For which of the following bird species is the standard deviation of the numbers of sightings shown for the four seasons least?
选项
A、Cardinal
B、Junco
C、Robin
D、Sparrow
E、Wren
答案
D
解析
Recall that the standard deviation of the numbers in a list is a measure of the spread of the numbers about the mean of the numbers. The standard deviation is directly related to the differences \x - m\ between the mean m and each number x in the list. The smaller the differences, the smaller the standard deviation. Thus to answer the question, look at the values of \x — m\ for each of the five bird species in the answer choices and determine which species has the smallest values.
Choice A, Cardinal. For cardinals, the numbers of sightings are 30, 18,11, and 20. The mean is approximately 20. Therefore the differences between the mean and the four numbers in the list are approximately 10, 2, 9, and 0.
Choice B, Junco. For juncos, the numbers of sightings are 12, 0, 0, and 6. The mean is approximately 5. Therefore the differences between the mean and the four numbers in the list are approximately 7, 5, 5, and 1.
Choice C, Robin. For robins, the numbers of sightings are 6, 12, 28, and 18. The mean is 16, and the differences between the mean and the four numbers in the list are 10, 4, 12, and 2.
Choice D, Sparrow. For sparrows, the numbers of sightings are 20, 19, 23, and 22. The mean is 21, and the differences between the mean and the four numbers in the list are 1, 2, 2, and 1.
Choice E, Wren. For wrens, the numbers of sightings are 0, 18, 30, and 12. The mean is 15, and the differences between the mean and the four numbers in the list are 15, 3, 15, and 3.
Consider how consistently small the differences are for the numbers of sightings of sparrows as compared to the differences for the other four species. From this you can judge that the numbers of sightings of sparrows has the least standard deviation. Thus the correct answer is Choice D.
This explanation uses the following strategies.
Strategy 4: Translate from a Figure to an Arithmetic or Algebraic Representation
Strategy 9: Estimate
转载请注明原文地址:https://tihaiku.com/zcyy/3355708.html
相关试题推荐
Thefollowingdatasufficiencyproblemsconsistofaquestionandtwostatements
Whichofthefollowingistheclosestapproximationof[img]2011q3/ct_egmatqj_eg
If(x-1)2=144,whichofthefollowingcouldbethevalueof2x?A、-26B、-22C、-11
Thesumofthenon-primenumbersbetween40and50,non-inclusive,isA、131B、176
Thefollowingdatasufficiencyproblemsconsistofaquestionandtwostatements
Thefollowingdatasufficiencyproblemsconsistofaquestionandtwostatements
Ifthesumoffiveconsecutiveoddintegersis5,whichofthefollowingcouldb
Ifrisnegativeandsispositive,whichofthefollowingmustbenegative?A、|r
Thefollowingdatasufficiencyproblemsconsistofaquestionandtwostatements
Thefollowingdatasufficiencyproblemsconsistofaquestionandtwostatements
随机试题
TheconqueringEuropeansdisplacedtheAborigines,killingmany,drivingoth
Itisquitecommonthatcustomersdon’tbargainaboutpricesinthatcity.A、常见的是
某工程双代号网络计划如下图所示,其关键线路有( )条。 A.2 B.3
关于缺铁性贫血的原因和发病机制的描述中,不包括A.胃大部切除术后影响铁吸收 B
下列哪种先天性心脏病可出现原发性左心衰竭A.法洛四联症 B.房间隔缺损 C.
脱水患儿累积丢失液量补足的时间应是A.30~60分钟 B.1~3小时 C.4
口腔念珠菌病按其主要病变部位可分为A.念珠菌性口炎、念珠菌性唇炎、念珠菌口角炎、
常用的隔热材料中,除硅藻土、矿渣棉、石棉以及其制品外,还有()。A:铸石 B:
某企业年初资产总额为500万元,年末资产总额为540万元,当年总收入为900万元
(2019年真题)关于建设工程质量保证金的说法,正确的是()。A.在工程项目竣
最新回复
(
0
)