2019沪科版八年级数学下册同步测试:20.2.2 数据的离散程度 第1课时

适用年级:初二
试卷号:620081

试卷类型:课时练习
试卷考试时间:2019/2/3

1.单选题(共2题)

1.
已知一组数据的方差为,数据为:-1,0,3,5,x,那么x等于(  )
A.-2或5.5B.2或-5.5C.4或11D.-4或-11
2.
一组数据13,14, 15,16,17的标准差是( )
A.0B.10C.D.2

2.选择题(共5题)

3.蓝细菌(蓝藻)与酵母菌的相同之处是(  )
4.蓝细菌(蓝藻)与酵母菌的相同之处是(  )
5.蓝细菌(蓝藻)与酵母菌的相同之处是(  )
6.

在初中即将毕业之际, 请你以张明的名义给英国笔友Brian写一封感谢信, 要点提示如下:

three years ago

a new comer, have no friends and feel lonely…..

During three years

Brain have written many letters to help you in different ways:

Encourage you to make more friends.

Tell you the ways how to learn English well

…….

…….

You have changed a lot, for example, ……..

invite him to come to Hangzhou to pay a visit…….

要求:

①词数:80--100个

②信的开头和结尾已给出, 不计入总词数

③要点齐全, 行文连贯, 可适当发挥

Dear Brian,

How time flies! We have been friends for three years. I'm writing to thank you for your help!

     Three years ago, ……         


Hope to see you soon!

                                                           Yours,

Zhang Ming


7.

在初中即将毕业之际, 请你以张明的名义给英国笔友Brian写一封感谢信, 要点提示如下:

three years ago

a new comer, have no friends and feel lonely…..

During three years

Brain have written many letters to help you in different ways:

Encourage you to make more friends.

Tell you the ways how to learn English well

…….

…….

You have changed a lot, for example, ……..

invite him to come to Hangzhou to pay a visit…….

要求:

①词数:80--100个

②信的开头和结尾已给出, 不计入总词数

③要点齐全, 行文连贯, 可适当发挥

Dear Brian,

How time flies! We have been friends for three years. I'm writing to thank you for your help!

     Three years ago, ……         


Hope to see you soon!

                                                           Yours,

Zhang Ming


3.填空题(共2题)

8.
已知一组数据,﹣2,3,1,6的中位数为1,则其方差为____
9.
已知数据:1,2,1,0,-1,-2,0,-1,这组数据的方差为______.

4.解答题(共1题)

10.
一次期中考试中A、B、C、D、E五位同学的数学、英语成绩等有关信息如下表所示:
 
A
B
C
D
E
平均分
标准差
数学
71
72
69
68
70
 

英语
88
82
94
85
76
85
 
 
(1)求这五位同学在本次考试中数学成绩的平均分和英语成绩的标准差;
(2)为了比较不同学科考试成绩的好与差,采用标准分是一个合理的选择,标准分的计算公式是标准分=(个人成绩-平均成绩)÷成绩标准差. 从标准分看,标准分大的考试成绩更好,请问A同学在本次考试中,数学与英语哪个学科考得更好.
试卷分析
  • 【1】题量占比

    单选题:(2道)

    选择题:(5道)

    填空题:(2道)

    解答题:(1道)

  • 【2】:难度分析

    1星难题:0

    2星难题:0

    3星难题:0

    4星难题:0

    5星难题:0

    6星难题:0

    7星难题:0

    8星难题:0

    9星难题:5