Math topic中文

Central tendency

mean, mode and median as measures of central tendency for a set of data

Practice questions

  1. 1某班第二组女生参加体育测试，仰卧起坐的成绩（单位：个）如下：43、41、39、40、37．这组数据的中位数是 ．
  2. 2车间生产同一种产品，某一星期日产量的情况如下：有22天是154154件，有33天是152152件，有22天是146146件，那么车间这个星期日产量的众数是 ___.
  3. 3The stem-and-leaf diagram shows the test scores of the boys and girls from a particular class. [Stem-and-leaf diagram pr…
  4. 4有三个数5，x，9，它们的平均数为6，则x为 ．
  5. 5The smallest of a set of five number is an even number and it is prime. The range and the mean is 7. The median is also…
  6. 6小李大学毕业到一家公司应聘英文翻译，该公司对他进行了听、说、读、写的英语水平测试，他的各项成绩((百分制))分别为7070、8080、9090、100.100.他这四项测试的平均成绩是(    )(\:\:\:\:) A…
  7. 7六(1)班1212名男生11分钟做仰卧起坐成绩如下：((单位：次)20    24    27    31    28    25    34    30    42    31    26    31)20\:\:\:\:24\:\:\:\:27\:\:\:\:31\:\:\:\:28\:\:\:\:25\:\:\:\:34\:\:\:\:30\:\:\:\:42\:\:\:\:31\:\:\:\:26\:\:\:\:31…
  8. 8A survey was carried out to find out the number of emails received in a week by each of a group of students. The table b…
  9. 9如果四个人的平均年龄是1212岁，且没有大于1515岁的，那么这四个人中年龄最小的可能是()(\quad)岁。 A. 33 B. 66 C. 1010
  10. 10The following stem-and-leaf diagram shows the scores of students in a math test. the median score, Answer ___ the interq…
  11. 11The marks of a group of 19 students in a test were recorded, as the marks are shown in the stem and leaf diagram. The mo…
  12. 12The following stem-and-leaf diagram shows the marks obtained by 20 pupils in a class test that has a total mark of 50. S…
  13. 13The masses of 20 bags, in kg, are measured. The results are shown on the stem-and-leaf diagram. Find the mean mass of th…
  14. 14The stem and leaf diagram below shows the marks obtained by 30 students in a Science test marked out of 80 marks. Find t…
  15. 15The cumulative frequency graph shows distribution of the waiting times before being served, in minutes, of 60 customers…
  16. 16Four students take an exam. Three of their scores are 7070, 8080, and 9090. If the average of their four scores is 7070,…
  17. 17The waiting time, t in minutes, for 40 customers at two phone service shops, Shop A and Shop B, are as follows. Calculat…
  18. 182014年6月份，某市一周空气质量报告中某项污染指数的数据是：31，35，31，32，30，32，31．这组数据的众数为 ；中位数为 ．
  19. 191010名工人某天生产同一个零件，个数分别是4545，5050，5050，7575，2020，3030，5050，8080，2020，3030，设这些零件的平均数为a−\overset{-}{a}…
  20. 20Electricity tariffs are regulated by the Energy Market Authority (EMA) of Singapore and revised quarterly to reflect the…
  21. 21The temperatures of eighteen girls in a class on a particular day are shown in the stem-and-leaf diagram. (Stem-and-leaf…
  22. 22The heights of 400 students in School A are recorded. The cumulative frequency curve below shows the distribution of the…
  23. 23Mr Tan designed two computer models X and Y. Both have the same manufacturing cost. Mr Tan engaged his existing client M…
  24. 24Leroy has written down four numbers. The mean of these numbers is 2x+y2x + y, the median is x+yx + y and the mode is x−yx - y…
  25. 25有一组数据：35，36，38，40，42，42，75．这组数据的中位数是（ ） A. 39 B. 40 C. 41 D. 42
  26. 26John owns a cleaning company that cleans office blocks. The number of employees in his company and their salaries in 202…
  27. 27The cumulative frequency curve shows the weekly expenditure on home deliveries of 160 households from Block W. Use the c…
  28. 28The masses of 20 bags, in kg, are measured. The results are shown on the stem-and-leaf diagram. Find the mean mass of th…
  29. 29一组数据22，33，xx，yy，1212中，唯一众数是1212，平均数是66，则这组数据的中位数是___.
  30. 30一次歌咏比赛中，10位选手的成绩分别是95分、80分、85分、81分、95分、88分、80分、85分、85分、70分．这组数据的众数是 ，中位数是 ．
  31. 31在2005年初中毕业会考中，抽查了10名同学的数学成绩如下：98，88，63，90，82，86，82，88，82，70．在这个问题中，样本容量、众数、中位数分别是（ ） A. 10，88，82 B. 10，82，84 C. 98，88，82…
  32. 32下列说法正确的是（ ） A. “明天的降水概率是80%”表示明天会有80%的地方下雨 B. 为了解学生视力情况，抽取了500名学生进行调查，其中的样本是500名学生 C. 要了解我市旅游景点客流量的情况，采用普查的调查方式 D. 一组数据5…
  33. 33某次考试，乐乐数学考了89分，语文考了88分．数学、语文、英语三科成绩的平均分是90分．她的英语成绩是（ ） A. 80分 B. 88分 C. 90分 D. 93分
  34. 34小明记录了自己5次1分钟踢毽的成绩，其中最好成绩是19下，最差成绩是10下，小明平均每分踢键数，可能是下列数据中的（ ） A. 10 B. 15 C. 19 D. 20
  35. 35The ages of 18 swimmers and 11 cyclists in a sports carnival race were recorded. The results are shown in the stem-and-l…
  36. 36Peter is shopping for an air conditioner. Peter writes down the duration he would use the air conditioner in the followi…
  37. 37A number NN is inserted into the list 2, 6, 7, 7, 28. The mean is now twice as great as the median. What is NN? A. 7 B…
  38. 38在某校举行的“艺术节”的文艺演出比赛中，九位评委给其中一个表演节目现场打出的分数如下：9.3，8.9，9.3，9.1，8.9，8.8，9.3，9.5，9.3，则这组数据的众数是 ，中位数是 ．
  39. 39In an experiment with 16 observations on x, the following results were obtained: ∑x=182\sum x = 182, ∑x2=3548\sum x^2 = 3548 One o…
  40. 40The cumulative frequency graph shows the distribution of times of the first 120 runners to finish a marathon in 2022. Th…
  41. 41The following bar graph represents the length (in letters) of the names of 19 people. What is the median length of these…
  42. 4212 students from class A took a Mathematics test. The table below shows the test marks of the students. However, two of…
  43. 43A class of 12 boys and 8 girls took a test. The girl's marks were 3, 6, 7, 8, 9, 9, 10 and 10. Find the mean mark for th…
  44. 44某校拟招聘一批优秀教师，其中某位教师笔试、试讲、面试三轮测试得分分别为9090分、8080分、9090分，综合成绩中笔试占40％40％，试讲占40％40％，面试占20％20％，则该名教师的综合成绩为 ___分．
  45. 45The box-and-whisker plots show the distribution of the masses (in grams) of eggs sold in Shop A and Shop B. There are 25…
  46. 46Six positive integers have a mean of 15, a median of 15 and a mode of 16. The range of these numbers is 7. Find the six…
  47. 47一组数据中,有一个数据变动, （ ___ ） 数就一定会变动。
  48. 48The diagram shows the number of students at soccer practice each weekday during last week. After computing the mean and…
  49. 49A researcher conducted a Particle Filtration Efficiency (PFE) test on surgical masks and reusable masks which have been…
  50. 50There are 20 cities in the County of Newton. Their populations are shown in the bar chart below. The average population…
  51. 51在20142014年重庆市初中毕业生体能测试中，某校初三有77名同学的体能测试成绩((单位：分))如下：5050，4848，4747，5050，4848，4949，48.48.这组数据的众数是 ．
  52. 52为了建设一个整洁、文明的城市，某校组织了以“讲文明、守秩序”知识竞赛活动从中抽取了5名同学的参赛成绩如下（单位：分）：80，90，70，100，80，则这组数据中位数和众数分别是（ ） A. 90，80 B. 70，80 C. 80，80…
  53. 53There are five numbers. Some information of the numbers are as shown. Range = 6 mean = 7 median = 8 mode = 9 Find the nu…
  54. 54The frequency table shows the reaction time, t seconds, for a chemical to change the colour of the litmus paper in 100 l…
  55. 55A class of 10 boys and 10 girls took a test. The girls' marks were 4, 5, 6, 7, 7, 7, 8, 8, 8 and 10. State the modal mar…
  56. 56Isha has written down five numbers. The mean of these numbers is 13.2, the median is 12 and the mode is 7. The largest n…
  57. 57The frequency table below shows the number of books read by a group of students in a month. Write down the least possibl…
  58. 58Gladys wrote down four numbers. The mean of these numbers is 13, the median is 12 and the mode is 10. Find the four numb…
  59. 59某年级参加数学竞赛的女生和男生人数比是1：3，这次竞赛的平均成绩是82分，其中男生的平均成绩是80分，女生的平均成绩是（ ） A. 82分 B. 84分 C. 86分 D. 88分
  60. 60The weights (in kg) of 14 students are measured and illustrated in the dot diagram. the range of the weights. Answer ___…