题干

丽华根据演讲比赛中九位评委所给的分数作了如下表格

平均数

中位数

众数

方差

8.5

8.3

8.1

0.15

如果去掉一个最高分和一个最低分,则表中数据一定不发生变化的是(  )

A:平均数

B:众数

C:方差

D:中位数

上一题 下一题 0.0难度 选择题 更新时间:2018-05-20 11:04:16

答案(点此获取答案解析)

D

同类题3

任务型阅读

    Are These the Best Years of Your Life?

    The ups and downs of life may seem to have no predictable plan. But scientists now know there are very clear life patterns that almost all people share. Even if you have passed some of your best years, you still have other good years to come.____

    When are you smartest? From 18 to 25, according to I. Q. scores; but you are wiser and more experienced with increasing age. You're sharpest in your 20's; around 30, mental abilities begin to decline, particularly your ability to do maths.____ Your vocabulary at age 45, for example, is three times as great as when you graduated from college. At 60, your brain possesses almost four times as much information as it did at age 21.

    ____You have the best physical sense of yourself from 15 to 24, when you feel energetic all the time. The best professional sense seems from 40 to 49. Before age 24, we believe that our happiest years are yet to come. Over 30, we believe that they're behind us. A National Health Survey agrees: After age 30, we “become more realistic and do not view happiness as a goal in itself. If we keep our health, achieve professional and emotional goals, then happiness, we feel, will follow.”

    ____Generally between 30 to 39, but the peak(顶峰)varies with different professions. Mozart wrote a symphony by age eight, and Mendelssohn composed his best-known work, A Midsummer Night's dream, at 17, but most of the great music was written by men between 33 and 39. Though the peak in most fields comes early—most Nobel Prize winners did their top research in their late 20's and 30's, creative people continue to produce quality work throughout their lives.____

A. When are you happiest?

B. When are you most creative?

C. But your ability to complete other tasks climbs.

D. The above gives you an accurate figure.

E. Certain good years seem to come later in life.

F. For people who are creative, there is no upper age limit.

G. The human life journey cannot be charted by a clear life pattern.

同类题5

阅读下面的文字,完成小题。

验钞机

加贝

    淇河市副市长梁醒刚到办公室,电话就响了。保卫科那头传来陌生的声音:“小梁,我知道你很忙,不得已才来找你,不会耽搁你多少时间的。”

    梁醒没有猜出叫他“小梁”的人是谁,便问“你是?”“我是赵德法啊!”来人小声说。“赵……你是赵老师?“梁醒终于听出来了,对方是他的初中班主任,也是淇河市下属县的前任财政局长,因贪污受贿被判了8年。

    面前的赵德法老师几年不见,头发全白了,没有当年意气风发的模样。

    梁醒给他倒了杯水,问有什么事。对方局促不安,半天没有说出一句话。于是,他主动说:“赵老师,有事尽管说,只要不违背原则,学生能办的,尽量安排。“梁醒可怜他的处境,但又怕他真给自己出难题,特意加了句“只要不违背原则”。最后才明白赵德法想让他帮着找事做。

    他小心翼翼地红着脸说,“我被判了刑,开除了公职,老婆孩子跟我断绝了关系,亲戚朋友也视我为眼中钉肉中刺,我现在……”他哽咽地说不下去了。

    梁醒心中一软,但口气强硬:“但是你能干啥呢?”他怯怯地说:“体力活是干不了,能不能把我安排到市政府大门口的保卫科。我不要钱,只要能维持基本的生活就行。”见梁醒没说话,他坐不住了:“小梁,难为你了。当财政局长这些年,我阅人无数,坏人的花花肠子一眼能看出来。你是副市长,圈子比我大,需要一个明辨是非的人替你把关。”

    梁醒心动了但不放心:“你只能帮我阅人,不能打着我的旗号办事,否则咱师生也会翻脸。”他喜形于色:“放心,我一定当好你的‘验钞机’!”

    他甄别的人都一一得到了验证。特别是梁醒的大学的铁哥们借故出差来玩,赵德法提醒他此人不可深交。没多久他就求梁醒办事,说有批货被海关查了,让梁醒出面打个招呼,并递了个厚厚的红包。梁醒最终没有答应这个铁哥们的要求。后来海关汇报从此人包中搜出了录音笔和微型拍摄器。梁醒惊出了一身冷汗。

    梁醒的妻弟在一个区里当副局长,工作干得好,因竞争局长过来找他。赵德法当即制止道:“工作真干得好就不用找人,找了人反而说不清了;干不好,打了招呼,组织也为难,群众意见也大。”听了建议,梁醒就没再过问。后来,妻弟当了局长,但他的竞争对手举报到省里,说梁醒给区里递了条子。省里一查,不但还了他一个清白,更提高了了他的威信。有了赵德法这个“验钞机”,梁醒顺风顺水,被省组织部列为市长人选。

    后来梁醒用合法方式让赵德法的恩人的儿子取得中标手续后,赵德法忙碌起来了。有天早晨,梁醒看到赵德法又黑又瘦,叫他去医院看看。赵德法眼圈一红:“没事。谢谢关心。”第二天保卫科说赵德法病重住院。梁醒大惊,直奔医院,在重症监护室找到了浑身上下插满管子的他。

    赵德法眼角滚出了一滴清泪,哆嗦着掏出一个纸包递给梁醒:“这是那小子的工程财务复印件,我仔细查看了,有问题,要马上停工。”喘了一口气,又说“我的病是肝癌晚期,时间不多了。我给家乡抹了黑,不能在死前再对不起政府和良心,更不能对不起你,不想背着‘贪官’这个骂名……唉,还不知族人肯不肯原谅我,让我进入祖坟啊!”

    两天后,梁醒站在殡仪馆赵德法的遗体前深深地鞠了一躬,哽咽着说:“赵老师,谢谢你这个无私的验钞机,替我验出了假币,让我避免了犯错。你放心,我一定亲自把你送回老家,说服你本家族人把你葬进祖坟……”