How many problems of statistics should be a specific process?

The level of significance is not given?

For the first question, the rejection domain should be calculated from the sample data and the hypothetical data at a specified confidence level (e.g., 95% for the common one), and then compared with the test statistic to decide whether to accept or reject the null hypothesis.

Regarding the second question, I also think that the two grades are in the same position in the class.

Summary. Q: What are degrees of freedom?

How is this determined? A: (Definition) The number of independent sample observations or the number of freely variable sample observations that make up the sample statistic.

Denoted by df. The reason for setting the degrees of freedom is that when the population mean is unknown, there is a limitation to using the sample mean to calculate the deviation (commonly used as small s) - to calculate the standard deviation (small s), the sample mean must be known first, and when both the sample mean and n are known, the sum of the data is a constant.

Therefore, the "last" sample data cannot be changed, because if it does, the sum changes, and this is not allowed. In layman's terms, there are 50 people in a class, and we know that their average score in the language is 80, and now we only need to know the results of 49 people to deduce the results of the remaining person. You can just report the results of 49 people, but you can't talk nonsense about the last person, because the average score has been fixed, and there is one less degree of freedom.

Q: What are degrees of freedom? How is this determined?

A: (Definition) The number of independent sample observations or the number of freely variable sample observations that make up the sample statistic. Denoted by df.

The reason for setting the degrees of freedom is that when the population mean is unknown, there is a limitation to using the sample mean to calculate the deviation (commonly used as small s) - to calculate the standard deviation (small s), the sample mean must be known first, and when both the sample mean and n are known, the sum of the data is a constant. Therefore, the "last" sample data cannot be changed, because if it does, the sum changes, and this is not allowed.

In layman's terms, there are 50 people in a class, and we know that their average score in the language is 80, and now we only need to know the results of 49 people to deduce the results of the remaining person. You can just report the results of 49 people, but you can't talk nonsense about the last person, because the average score has been fixed, and there is one less degree of freedom.

This question. Find the following fractions

The title is like that, and it says the meaning.

Given a small probability a, at the confidence level, the confidence interval at the overall level.

That's it? Hello, yes, this is the abbreviation, roughly meaning.

Summary. Hello dear, Question D: To determine whether the population mean is likely to be greater than the hour, we can use statistical inference methods.

According to the central limit theorem, the distribution of the sample mean will be close to a normal distribution, even if the population distribution is not normal. Since the sample size is 30, a normal distribution can be used to approximate the distribution of the sample mean. In a normal distribution, the standard deviation of the sampling distribution of the mean, also known as the standard error, can be estimated by dividing the population standard deviation by the square root of the sample size.

In this case, the standard error is 30 To determine whether the population mean is likely to be greater than the hour, we can calculate the difference between the sample mean and the sample mean by subtracting the hypothetical population mean ( and then dividing by the standard error. z = sample mean - population mean) standard error If the z-score is greater than at the 95% confidence level), the assumption that the population mean is less than the hour can be rejected.

Since the question does not give sample data, the z-score cannot be calculated. You'll need to provide sample data to make specific calculations.

D and E.

The dee of the fourth question

Okay, dear. Hello dear, Question D: To determine whether the population mean is likely to be greater than the hour, we can use statistical inference methods.

According to the central limit theorem, the distribution of the sample mean will be close to the normal detoxification distribution, even if the population distribution is not normal. Since the sample size is 30, a normal distribution can be used to approximate the distribution of the sample mean. In a normal distribution, the standard deviation of the sampling distribution of the mean, also known as the standard error, can be estimated by dividing the population standard deviation by the square root of the sample size.

In this case, the standard error is 30 To determine whether the population mean is likely to be greater than the hour, we can calculate the difference between the sample mean and the sample mean by subtracting the hypothetical population mean ( and then dividing it by the standard comma error. z = sample mean - population mean) standard error If the z-score is greater than at the 95% confidence level), the assumption that the population mean is less than the hour can be rejected.

Since the question does not give sample data, it is not possible to calculate the z-score. You'll need to provide sample data to make specific calculations.

Question E: To estimate the average time to win for this champion, you can use the sample and reputation mean as an estimate. According to the central limit theorem, the sample mean segment value is an unbiased estimate of the population mean.

In this case, the sample mean is the average of the 30 samples given. You can add up the winning masks of these 30 samples and divide by 30 to calculate the sample mean.

It is estimated that you are not a scholar yourself, and we also know this when we learn

It's a feeling of winding.

First of all, the DAO

The inner p-value is a probability value that tests the capacity of the statistic.

The probability of occurrence. Or the probability of a sample observation or a more extreme outcome if the null hypothesis is true.

If the p-value is small, the probability of this happening is small, and if it does, according to the principle of small probability, we have reason to reject the null hypothesis, and the smaller the p-value, the better the reason for us to reject the null hypothesis.

The p-value can also be said to reflect the probability value of the inconsistency between the observed actual data and the null hypothesis.

You have to understand what the p-value actually means, and you have to know what your null hypothesis is.

And then there's the problem you mentioned earlier, the mean test for matching samples. It depends on whether the specific problem is a large sample or a small sample, if it is a large sample, the test is z-value, and if it is a small sample, it is a t-value test. The size of the sample is 30 for the boundary, I think that you know.

The x+s you wrote above should be the δ of the mean plus or minus of x, not s. This is the standard error (also known as sampling error) of the mean plus or minus of the sample

I guess what I'm saying isn't very clear. If nothing is unclear, just say hello.

After reading the above answer, I think it's very good, I don't know whether the landlord is engaged in theoretical statistics or applied statistics, if it is in the application statistics, the p value is less than, it means that the difference between the average of the two sets of data is significant; If the p-value is greater than that, the difference between the mean of the two groups of data is not significant within the 95% confidence interval.

Lazy people!

1. On the basis of the analysis of the phenomenon, a number of representative units are consciously selected for investigation, and this kind of investigation belongs to the key investigation. （x ）

2. Generally speaking, the indicator is always attached to the whole, and the overall unit is the direct bearer of the mark. （

3. If the completion degree of the output plan of the three enterprises A, B and C this year is % and 105% respectively, then the average completion degree of the output plan of the three enterprises is 100%. x ）

4. The object of statistical research is the quantitative aspect of the objective phenomenon as a whole. （x ）

5. The grades of the three students are different, so there are three variables. （

6. Generally speaking, the index is always attached to the whole, and the overall unit is the direct bearer of the mark. （√

7. The key units of the key investigation are determined according to the current work priorities. （

8. When compiling the number of times distribution series, the income of 800 yuan should not be classified into the group of 600-800 yuan, but should be recorded in the group of 800-1000 yuan. （

9. The planned sales of a department store in 2001 increased by 10% compared with 2000, but the result was only an increase of 5%, so the store's sales plan task was completed by 50%.

10. If the variance of a set of arrays is known to be 9 and the coefficient of variation is 30%, then its average is equal to 30. （x ）

Average grade = median value of each group * frequency of each group, the sum of each group divided by 50 standard deviations = the median value of each group - the sum of the squares of the mean multiplied by the frequency and divided by 50, and the number obtained can be obtained by the square of the square.

Standard deviation coefficient = standard deviation divided by the mean.

Whose standard deviation is smaller, whose average grade is more representative, because it shows that the concentration trend is large, the above is a number that I have roughly calculated, I hope it can help you.

Solution: Suppose the production plan for the year 2016 is 1

Then the actual output in 2016 is 1 * percentile sign can not be typed out and written directly, sorry) The output in 2016 is 30% higher than the output in 2015, and the actual output in 2015 can be obtained:

Then (percent sign = ?)

The answer is up to you on paper. Hope.