首页
登录
职称英语
Six hundred applicants for several post office jobs were rated on a scale from 1
Six hundred applicants for several post office jobs were rated on a scale from 1
游客
2024-01-12
56
管理
问题
Six hundred applicants for several post office jobs were rated on a scale from 1 to 50 points. The ratings had a mean of 32.5 points and a standard deviation of 7.1 points. How many standard deviations above or below the mean is a rating of 48 points? A rating of 30 points? A rating of 20 points?
选项
答案
48 points is 15.5 points above the mean, or approximately 2.2 standard deviations above the mean.
30 points is 2.5 points below the mean, or approximately 0.4 standard deviation below the mean.
20 points is 12.5 points below the mean, or approximately 1.8
解析
Let d be the standard deviation, so d = 7.1 points. Note that 1 standard deviation above the mean is
32.5 + d = 32.5 + 7.1 = 39.6
and 2 standard deviations above the mean is
32.5 + 2d = 32.5 + 2(7.1)= 46.7
So 48 is a little more than 2 standard deviations above the mean. Since 48 is actually 15.5 points above the mean, the number of standard deviations that 48 is above the mean is
≈2.2. Thus, to answer the question, we first found the difference from the mean and then we divided by the standard deviation. The number of standard deviations that a rating of 30 is away from the mean is
where the negative sign indicates that the rating is 0.4 standard deviation below the mean.
The number of standard deviations that a rating of 20 is away from the mean is
where the negative sign indicates that the rating is 1.8 standard deviations below the mean.
To summarize:
48 points is 15.5 points above the mean, or approximately 2.2 standard deviations above the mean.
30 points is 2.5 points below the mean, or approximately 0.4 standard deviation below the mean.
20 points is 12.5 points below the mean, or approximately 1.8 standard deviations below the mean.
One more instance, which may seem trivial, is important to note:
32.5 points is 0 points from the mean, or 0 standard deviations from the mean.
转载请注明原文地址:https://tihaiku.com/zcyy/3355381.html
相关试题推荐
CustomsOfficer:Next...Uh,yourpassportplease.Woman:Okay.Customs
Ournewhouseisvery__________formeasIcangettotheofficeinfiveminutes
Ihavebeenlookingforthisbookforseveralweeks,and_________Ihavefound
Mr.Smithwillbe_________theofficenextweekwhenthemanagerisaway.A、inch
Thecomputersmadebyourcompanysellbest,butseveralyearsagonoonecould
Thenoticewaswritteninseverallanguages_________foreigntouristsshouldmisu
Ahundredyearsagoitwasassumedandscientifically"proved"byeconom
Ahundredyearsagoitwasassumedandscientifically"proved"byeconom
Ahundredyearsagoitwasassumedandscientifically"proved"byeconom
Ahundredyearsagoitwasassumedandscientifically"proved"byeconom
随机试题
Thepassageismainlyaboutwhyandhowtoplantmoretreestomakeuniversities
“大五”人格理论所指的人格特质表现是()A.公正性 B.和悦性 C
B
企业与股东、银行、新闻媒体之间的沟通属于()A.内部沟通 B.纵向沟通 C
高层民用建筑中的通廊式住宅,在哪种情况下应设防烟楼梯?()A.10层以上
以下属于医疗事故的是A.在紧急情况下为抢救垂危患者生命而采取紧急医学措施造成不良
共用题干 周某购买了一套已装修的建筑面积为160㎡的商品住宅,总计房价款为80
2020年1-10月,我国规模以上互联网和相关服务企业(简称互联网企业)完成业务
下列场所均采用湿式自动喷水灭火系统,洒水喷头的选项符合规范要求的是()。A
桃:果汁:饮料()A.水稻:小米:粮食 B.芝麻:油:香油 C.煤:电:
最新回复
(
0
)