## 这个作业是来自英国的关于用R语言完成抽样调查的作业代写，下面是具体作业详情内容：

PUBL0055 Introduction to Quantitative Methods

A.计算起草人和未起草人之间的平均信任度差异。提供简要解释。

B.解释“抽样分布”的概念。样本分布的形状是什么

C.使用公式计算标准差和均值差的95％置信区间

D.现在通过使用线性回归来估计相同的效果。将结果显示在表格中，解释回归系数并将这些估计值与先前获得的估计值进行比较。可以起草系数在该模型中被解释为因果关系？解释为什么能或者为什么不能。

A.拟合一个线性回归模型，该模型除了包括种族种族和出生年份外还包括协变量治疗变量。制作一个包含此模型和上面问题1 D部分中的模型的表。

B.在您适合A部分的多元回归模型中，充分解释其幅值和统计数据RaceEthnicity变量的水平Black的系数的显着性。

C.从Vote12Obama，AffordableMistake，伊拉克Mistake，AttendedPolEvent和意识形态可能会告诉您有关起草的长期影响态度或政治行为。估计起草对这些结果的平均治疗效果。
（出于这个问题的目的，您可以运行带有二进制因变量的线性回归模型。）产生图表或表格来展示您的结果。写一份简短的报告，总结您的发现。

Question 3

Use a multiple linear regression model to investigate whether the effects of being drafted on levels of trust are different for the different race/ethnicity groups defined in the variable RaceEthnicity (White, Black and Hispanic). Write a short essay describing what you find,including an assessment of the strength of the evidence for any differences (or lack thereof) that you find.

In writing this essay, you might want to:
• Provide relevant descriptive statistics for the key variables
• Explain how you set up the model(s) to make this assessment
• Present your regression estimates in a table along with the other models for trust that you fit in Questions 1D and 2A.
• Construct fitted values for relevant cases to illustrate the relationships described by the model.

Please note that you need not present all of these, you should aim to clearly describe the data and what they can tell us about differences in the long-run effects of being drafted for individuals in the three race/ethnicity categories in the data set.

Question 4

A. Calculate, compare and interpret the yearly outcomes by treatment group. What does this tell you?

B. Using the data from the years 2007 (the last year of the pre-treatment period) and 2008 (the first year of the post-treatment period), compute the difference-in-differences estimate of the effect of municipal merger on public service delivery costs.

C. Use an appropriate linear regression to calculate the same difference in differences estimate that you calculated in part B. Show that you get the same numerical value, and use the results of the regression to test the null hypothesis that the difference in differences is equal to zero. Interpret your results in terms of the research question posed at the beginning of this section.