环境统计学2007B试卷答案

杭州师范学院生命与环境科学学院2006-2007学年第一学期期末考试

《环境统计学》试卷（B）答案班级：学号：姓名：

一、名词解释（共20分，每小题4分）

1. 数据和数据类型（Data and types of data）

The numerical facts that reflect the variable are data (One numerical fact is a datum) : Quantitative data, ranked (ordinal) data, and categorical (nominal) data

2. 参数分析须满足的三个假设（The three assumptions for parametric analyses）Normality, additivity, and homogeneity

3. 正态分布曲线的特点（Properties of the normal distribution curve）

●Normal distribution curves are bell-shaped and bilaterally symmetrical. The tails of the curve

approach the X-axis, but never touch it. Although the graph will go on indefinitely, the area under the graph is considered to have a unit of 1.00

●Also unique about the normal distribution curve is that the mean, median, and mode are the

same value

●The mode and median can be estimated by simply looking at a graph: the mode is the value

with the highest frequency, and the median is the middle point. It is harder to estimate the mean, however, as that depends on the range of values

4. 协方差分析的基本步骤（The general procedures for analysis of covariance）

●To examine if data are suitable for parametric analyses

●To examine if the involved linear regression lines are statistically significant

●To examine if the involved linear regression lines are parallel. If so, then calculate the

common slope

●To examine if the intercepts differ significantly. If so, then correct observed values

●To show differences in adjusted means among sample using multiple comparison

5. 现代科学研究的基本步骤（The general procedures for modern scientific researches）

●Observation of a particular event

●Statement of the problem

●Formulation of a hypothesis

●Making a prediction

●Design of the experiment

●Statistical analyses of data

●Conclusion

二、基础统计分析题（共20分）

1. 用下表人类头发颜色观测频次（O）的抽样数据，要求：（1）填写头发颜色的理论频次分布；（2）用卡方好适度检测和对数似然比例（G检验）检测人类黑色、棕色、白色、金色和红色头发颜色是否吻合5: 3: 2: 2: 1的颜色分布[The following sample data are recorded as the observed frequencies (O), by which you may use to test whether the sample comes from a population having a 5: 3: 2: 2: 1 color pattern of black to brown to white to blond to red hair colorations. You are asked: (1) to show the expected frequencies (E), and (2) to decide the trueness of the null hypothesis (H0) using Chi-square goodness of fit (X2test) and Log-likelihood ratio

G = 4.80, df = 4, P > 0.05

X2 = 4.78, df = 4, P > 0.05

学业表现（Please fill the following uncompleted form and then use Mann-Whitney test to examine if the performance of students is the same under two teaching assistants）(10 points)

Teaching assistant A Teaching assistant B Grade Range of grade Grade Range of grade

A 2.5 A 2.5

A 2.5 A 2.5

A- 5.5 B+ 7.5

A- 5.5 B+ 7.5

B 10 B 10

B 10 B-12

C+ 13.5 C 16.5

C+ 13.5 C 16.5

C 16.5 C-19.5

C 16.5 D-24

C-19.5 D 22.5

D 22.5

D+ 21

U = 49.5, U’ = 93.5, P = 0.202