1. standard error of the mean
The value of the standard deviation of all possible sample means, called the standard error of the mean , expresses how the sample mean varies from sample to sample. n x /σσ=
2.Population
A population consists of all of the members of a group about which you want to draw a conclusion.
3.Parameter
A parameter is a numerical measure that describes a characteristic of a population.
4. Frequency distribution
A frequency distribution is a summary table in which the data are arranged into numerically ordered class groupings.
5.Range
The range is the simplest numerical descriptive measure of variation in a set of data.
smallest est l X X Range -=arg
6.conditional probability p 81
conditional probability refers to the probability of event A ,given information about the occurrence of another event B .
()()()
B P AandB P =B \A P 7. sampling with replacement
The sampling with replacement means that after you select an item, you return it to the frame where it has the same probability of being selected again.
8. Sampling distribution
To use the sample statistic to estimate the population parameter, you should examine every possible sample that could occur. A sampling distribution is the distribution of the results if you actually selected all possible samples.
18. Type Ⅰ error
A Type I error occurs if you reject the null hypothesis H 0 when it is true and should not be rejected.The probability of a Type I error occurring is α.
9. Type Ⅱ error
A Type 2 error occur s if you do not reject the null hypothesis H 0 when it is false and should be rejected.The probability of a Type 2 error occurring is β.
10. SSW
The within-group variation, usually called the Sum of squares within groups(SSW),measures the difference between each value and the mean of its own group and sums the squares of these differences over all groups.
11. Variables
Variables are characteristics of items or individuals.
12.Sample
A sample is the portion of the population selected for analysis.
13.Statistic
A Statistics is a numerical measure that describes a characteristic of a sample. 1 6. Coefficient of variation
The coefficient of variation,denoted by the symbol CV ,measures the scatter in the data relative to the mean.It is equal to the standard deviation divided by the mean, multiplied by 100％.
()
00100S/CV X = 19. SSR (可解释变量的总方差)
The Regression sum of squares(SSR) is equal to the sum of the squared differences between the predicted value of Y and Y , the mean value of Y .
20. Residual
The residual is equal to the difference between the observed value of i Y and the predicted value of i Y . i i Y -E i Y =
21.stratified sample
In stratified sample ,first subdivide the N items in the frame into separate subpopulations, or strata. A strata is defined by some common characteristic. Then select a simple random sample within each of the strata, and combine the results from the separate simple random samples.
22.one-tail test
When the entire rejection region is contained in one tail of the sampling distribution of the test statistic, the test is called a one-tail or directional test.
23.one-way ANOVA
The ANOVA is used to compare the means of more than two groups. When the groups are different levels of one factor, as is the case in this section, the ANOVA procedure used is referred to as a one-way ANOVA.
24.simple linear regression
Sample standard deviation is the square root of the sum of the squared differences around the mean divided by the sample size minus one.。