1、6.6, 120.
2、 10.3、80.
4、28.2.5、 10,2 1.
6. Average donation per class 100 yuan.
7, 9.47, if you remove 9.8 and the lowest score.
9.2, then the athlete's final score is 9.46.
Points.
8.( 1) omitted;
(2) The average sample is about1.17 (kg);
(3) It is estimated that the total mass of the fish in the reservoir is about 1 17000(kg).
3.2 Median and mode answers
1、0.5,6.
2、( 1)22;
(2)73;
(3) 146.
3、20min,20min,2 1.75min。
4、( 1) 16;
(2)60 points, 60 points, 58.75 points.
5. Average age of male football players in this school 15.
Years old, indicating that the average age of team members is 15 years old;
Most of them are 15 years old, indicating that the team has the most players aged 15 years old; The median is 15 years old, which means teams older or younger than 15 years old.
Each member accounts for about half.
3.3 Use a calculator to find the average answer.
1、0.5,6.
2、( 1) 1 18;
(2)20 12, 120;
(3)96.
3.( 1) The quality of canned food produced by this food factory on another day is all.
It's the population, and everyone's quality can be.
It is an individual, and the quality of 100 cans extracted from it.
The quantity is the total sample, and the sample size is
100.
3.4 Different answers
1、 14℃.
2.b is relatively stable.
3. The average scores of Xiaoli and Xiaoping are 14.6s and respectively.
14.49s, with a variance of 0.206(s? ) and 0.6 13
(s? ), from the average point of view, Xiaoping can be selected to participate in the competition.
Judging from the stability of performance, Xiaoli can be selected for the competition.
4.( 1) student b;
②s? A=0.026(mm? );
s? B=0.008(mm? ),
s? A is greater than s? B, the processing quality of student B is relatively stable;
(3) As can be seen from the trend in the figure, although the processing quality of student A fluctuates greatly in the front, it gradually stabilizes and predicts student A..
Student A can also be selected to take part in the competition.