The extreme range of 1. 10, 20, 40, 30, 80, 90, 50, 40, 40, 50 is
Group number 12345678
Frequency114121313 x1210.
From 40 to 70 A.D.
2. Divide 100 data into 8 groups, as shown in the right table:
The frequency of the sixth group is ()
12 b . 13 c . 14d . 15
3. Divide the sample statistics with 40 data into 6 groups. If the frequency of a group is 0. 15, the frequency of the group is ().
A.6 B.0.9 C.6.67 D. 1
4. Known samples: 10, 8, 6, 10, 8, 13, 1 1, 12, 7, 9.
a . 5.5 ~ 1 1.5 b . 7.5 ~ 9.5 c . 9.5 ~ 1 1.5d . 1 1.5 ~ 13.5
5. Given the samples: 25, 28, 30, 27, 29, 3 1, 33, 36, 35, 32, 26, 29, 3 1, 30, 28, then the frequency range is ().
a . 25 ~ 27 b . 28 ~ 30 c . 3 1 ~ 33d . 34 ~ 36
6. To understand the size of the proportion of eighth-grade students in a certain range, you need to know the corresponding sample ()
A. Mean B. Variance C. Mode D. Frequency distribution
7. In the histogram of frequency distribution, the following conclusion holds ()
A. the sum of each group of frequencies is equal to n B, and the sum of each group of frequencies is equal to 1.
C. the sum of each group of frequencies is equal to n d, and the sum of the heights of each group of rectangles is equal to 1.
8. Take 40 math papers, of which the frequency below 60 points is 5, so the frequency of failing is ().
a . 0.5 b . 1 c . 0. 125d . 0.25
9. There are 48 students in one class. In a math exam, the score is only an integer. Count the score and draw a histogram of frequency distribution (the horizontal half axis represents the score, and the score between 50.5- 100.5 is divided into five groups, with the interval of 10, and the vertical half axis represents the ratio of frequency to interval). As shown in the figure, the height ratio of the small rectangle from left to right is 60.
A.9 B. 18 C. 12 D.6
10. Xiao Min counted the favorite subjects of 50 students in the class (each student only chooses one subject). The statistical results show that the favorite frequencies of mathematics and science are 13 and 10 respectively. The favorite frequencies of Chinese and English are 0.3 and 0.2 respectively, and the rest of the students like society best, so the following statement is wrong ().
People who like Chinese best. B, the person who likes society the least.
C the sum of the number of people who like math best and the number of people who like Chinese best exceeds half of the total number.
The number of people who like science best is less than that who like English best.
Fill in the blanks (3 points for each small question, 30 points for * * *)
1 1. One physical examination, among the 24 boys in Grade One (1), 2 were 1.48m, and 7 were between 1.50m and 1.60m, with the height/kloc-.
12. Sort out 2000 data. In the frequency distribution table, the sum of each group of frequencies is equal to _ _ _ _ _, and the sum of each group of frequencies is equal to _ _ _ _ _.
13. Given a sample of 40 data, divide it into six groups. The frequencies of the first group to the fourth group are 10, 5, 7 and 6 respectively, and the frequency of the fifth group is 0. 10, so the frequency of the sixth group is _ _ _ _ _.
14. There are 40 groups of data * * *, which are divided into 6 groups. The frequencies of 1 ~ 4 groups are 10, 5, 7 and 6 respectively, and the fifth group accounts for 10% of the total, so the frequency of the sixth group is _ _ _ _ _.
15. There are 48 students in one class. In a math exam, the scores are only integers, and their scores are counted. Draw the histogram of frequency distribution (the horizontal axis represents the score, and the score between 50.5- 100.5 is divided into five groups, with a group spacing of 10, and the vertical axis represents the ratio of frequency to group spacing).
16. In order to understand the physical condition of primary school students, students of the same grade in a primary school were selected for skipping test, and the obtained data were sorted out and divided into four groups, and the histogram of frequency distribution was drawn. It is known that the three groups of frequencies from left to right are 0. 1, 0.3 and 0.4 respectively, and the first group of frequencies is 5, so the fourth group of frequencies is _ _ _ _ _ _.
17. Select 100 resistors of the same specification produced by a factory to measure and get a set of data. The maximum value is 1 1.58ω, and the minimum value is 10.72ω. When sorting out this set of data, make sure that the group spacing is 0. 10.
18. In a basketball training, Xiao Ming practiced shooting and made 40 shots, including 25 shots, so the frequency of Xiao Ming's shots was _ _ _ _ _ _ _.
19. In order to know the height of boys in a junior high school, a sample with a capacity of 60 (the height of 60 students, in centimeters) was taken from a middle school there. The grouping situation is as follows:
Grouping147.5 ~155.5155.5 ~163.5 ~171.51.
Frequency 6 2 1 m
Frequency a0. 1
Then a = _ _ _ _ _ _ _ and m = _ _ _ _ _.
20. This year, Zhejiang Education Network launched online teaching. In order to know the online study time of the students in Class 38, junior high school, the head teacher investigated the online study time of 40 students in this class one day. After sorting out the data (taking integers), he drew a histogram of frequency distribution as shown in the figure. It is known that the frequencies of each group are 0. 15, 0.25 and 0.35 from left to right respectively. According to the information provided by the bar chart, the number of students studying online for100 ~19 minutes on this day is _ _ _ _ _. If only the online study time of these 40 students is taken as the survey result, is this reasoning reasonable? (Fill in "reasonable" or "unreasonable").
Iii. Answering questions (60 points)
2 1.(8 points) In order to know the math scores of 250 students in the junior high school entrance examination, the math scores of 50 students were analyzed, and the result was 94.5. The following is the frequency distribution table of 50 students' math scores.
Answer the following questions according to the conditions given in the question:
(1) During this sampling analysis, the sample is _ _ _ _ _ _ _ _;
(2) The data in the frequency distribution table are a = _ _ _ _ _ _ _ _, and b = _ _ _ _ _ _ _ _.
(3) It is estimated that the average math score of this entrance examination in the third grade of our school is around _ _ _ _ _ _ _ _;
(4) In this entrance examination, the number of students whose math scores in the third grade of our school are in the range of 90.5 ~ 100.5 is about _ _ _ _ _.
frequency table
Packet frequency cumulative percentage
60.5 ~ 70.5 3a
70.5 ~ 80.5 positive -60. 12
80.5 ~ 90.5 plus 90. 18
90.5 ~ 100.5 Zheng Zheng 17 0.34
100.5-110.5 plus B0.2
110.5 ~120.5 plus 50. 1
Total 50 1
Group frequency cumulative percentage
0~ 19.5
19.5~39.5
39.5~59.5
59.5~79.5
79.5~99.5
Total 50
22.(8 points) The following is the histogram of the frequency distribution of the scores of 50 students in a math exam (the score is not data, but percentile), as shown in the figure.
(1) List the frequency distribution table;
(2) the number of people who passed the exam and the passing rate (more than 60 points);
frequency table
23.( 10) The eyesight problem of junior middle school students has been widely concerned by the whole society. Relevant departments of a city conducted a sampling survey on the eyesight of 30,000 junior high school students in the city. The following figure is a histogram of frequency distribution drawn by using the obtained data (the height of the rectangle indicates the number of students in this group). According to the information provided in the picture, the following questions are answered:
(1) How many students were sampled in this survey?
(2) What does the sample in this question mean?
(3) As shown in the figure, 4.9-5. 1 (including 4.9 and 5. 1) has normal vision, so how many junior high school students in the city have normal vision?
26.( 12) The teacher wants to know how much time students spend on their way to school every day, so he asks everyone to write down the one-way time to come to school every day. The following are the time (minutes) spent by 30 students in the class on one-way trip: 20, 20, 30, 15, 20, 25, 5, 65438+. 10,20,25,30,20, 15,20,20, 10,20,5, 15,20,20,20,5, 15.
(1) In this statistic, how many minutes does it take for a one-way trip to have the maximum frequency?
(2) If these data are divided into three grades of less than 20 minutes, equal to 20 minutes and more than 20 minutes, what is the number of people in each grade? And represented by a fan-shaped statistical chart;
(3) If the teacher asks a classmate at random, do you think the teacher is most likely to get the answer in a few minutes?
That's enough, hehehehehehe