In a questionnaire survey of a sample of primary and secondary school students, there was such a que

Someone once said, "The fewer people you hate, the more joy you will have; If you make people you hate, you'll be happier. "I think that's about helping others.

In the real society, there will be many people who hate people, but what they can do is indeed what they should do, and holding affirmation shows that people who are sure are not thinking, because young children still have a vague concept of the words "hate" and "help", thinking that people should help others, let alone what they can do.

And when I grow up, the deeper concept of "hate" becomes clearer and clearer. The more disliking the ingredient in your mind, the less you will have the instinct to love and help others.

As you approach adulthood, complex thoughts will force you to try to ruin the lives of the people you hate, so as your thoughts mature, you will increasingly refuse to help those you hate. It doesn't matter if you can have the ability to help him.

Once, Hart and his mom came back from their hometown and sat on the number six bus. Mom sat in the back, and Hart sat in the seat closer to the car door, playing games on Mom's phone.

Hart was in the middle of his game, when suddenly the car stopped, and an old man and a grandmother came up. However, there were so many people in the car that there were no seats left, so the old man and grandmother had to stand not far from Hart, and as soon as the car started, they staggered and could not stand steadily.

As the sun brightened, Hart gradually saw that these two people were the ones who often stole grandma's vegetables and were always scolding. But thinking of their age, I gave up my seat.

Don't be a little bit older because you're older, the older you get, the less affirmations you have, which shouldn't be ...

In general, the larger the sample size, the more representative the sample will be of the population.

However, considering the cost factor, we need to scientifically formulate the sample size within the allowable error range, and balance the relationship between the survey cost and the survey accuracy.

Theoretically, to achieve a 95% confidence rate, more than 300 sample sizes are sufficient. If a group study is to be conducted, the quota for each group should be no less than 30 samples, and the quota for urban groups should not be less than 100;

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Preferably probabilistic sampling, stratified, clustered, and multi-stage, but this is more difficult to achieve. That's why we often use random sampling.

It is recommended that you use Form Master to do a questionnaire, which I usually use.

Investigating the size of the shoes worn by each student in your class is a comprehensive survey;

Investigate the service life of a batch of washing machines, and select 5 of them for sampling investigation;

Surveying the annual income of all households in a community is a comprehensive survey;

Investigating the hobbies of your classmates in your grade is a comprehensive survey; Envy.

Therefore, choose the brother to pick up this base: b

84*703 Huijisun (626+703+780)=28

Since the proportion of high school students in the sample is 703 (626+703+780), the proportion of high school students in the sample should also be equal to 703 (626+703+780).

According to the figure, it can be obtained:

A total of (15 + 30 + 20 + 35) = 100 people, and the frequency of participating in scientific and technological activities is 20, then the frequency of participating in scientific and technological activities.

So the answer is:

1) 24 30%=80 (students), A: A total of 80 students were selected in this survey;

3) According to the title: 360° 26

117°, A: In the fan chart, the central angle corresponding to the "bus" part is 117°;

4) According to the title: 1600 10

200 (students), A: It is estimated that there are about 200 students in the school who go to school by private car

1) 24 30%=80 (students), A: A total of 80 students were selected in this survey;

3) According to the title: 360° 26

117°, A: In the fan chart, the central angle corresponding to the "bus" part is 117°;

4) According to the title: 1600 10

200 (students), A: It is estimated that there are about 200 students in the school who go to school by private car