高三年上学期期末考试中,某班级数学成绩的频率分布直方图如图所

高三年上学期期末考试中,某班级数学成绩的频率分布直方图如图所示,数据分组依次如下:[70,90),[90,110),[100,130),[130,150),估计该班级数学成绩的平均分等于(  )

A.112  B.114  C.116  D.120

答案

B【考点】频率分布直方图.

【专题】概率与统计.

【分析】根据频率分布直方图,利用组中值×对应的频率,求和得出数据的平均值.

【解答】解:根据频率分布直方图,得;

该班级数学成绩的平均分是

=80×0.005×20+100×0.015×20

+120×0.02×20+140×0.01×20

=114.

故选:B.

【点评】本题考查了根据频率分布直方图,求数据的平均数的应用问题,是基础题目.

相关题目

Last term our maths teacher set such a difficult examination problem ______ non
Last term our maths teacher set such a difficult examination problem ______ none of us worked out.      A.that        B.as      C.so that      D.which
When you are reading fast,your eyes will be one or two word groups ahead of___
When you are reading fast,your eyes will be one or two word groups ahead of______ your mind is taking in. A.one                   B.the other                   C.th
如果A(a,b)与B(3,1)关于y轴对称,则a+b =           
如果A(a,b)与B(3,1)关于y轴对称,则a+b =           
函数在内有极小值,则( ) A.     B.    C.     D.
函数在内有极小值,则( ) A.     B.    C.     D.
回收硫磺主要来自石油和天然气,我国每年约从炼油中回收
回收硫磺主要来自石油和天然气,我国每年约从炼油中回收硫磺8万吨,从天然气加工中回收硫磺9万吨。若回收的硫全部用于制硫酸,则可生产硫酸的质
Don’t     to tell us if you have a problem.We’re friends,aren’t we
Don’t     to tell us if you have a problem.We’re friends,aren’t we?A.worry              B.apologize          C.promise                  D.h
 She missed the plane, _____ driving very fast to the airport.    A. unless 
 She missed the plane, _____ driving very fast to the airport.    A. unless      B. despite     C. though      D. without
Taking away a city’s rubbish is a big job. Every day trucks come into a city
Taking away a city’s rubbish is a big job. Every day trucks come into a city to collect it. Most rubbish is made up of things we can’t eat or use. If we kept these things we would soon have a mo

最新题目