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Question: 1. Find a recent survey reported in a newspaper, magazine or on the web. Briefly describe the survey. What are the target population and sampled population? What conclusions are drawn from the survey in the article. Do you think these conclusions are justified? What are the possible sources of bias in the survey? Please be brief. 2. A doctor at a university with 3,100 students is interested in knowing how many of the students get a flu shot. i) Last year in a random sample of 100 students she found that 65 had gotten a shot. Give the usual 95% confidence interval for the true proportion of students that got a shot. i) This year she would like to know how large her sample size should be for the resulting 95% confidence interval for p, the proportion of students who had a shot, is no longer than 0.08. 3. On the clas web page under Data sets you wil se the link, house sales. This is a link to the R data file glen.rda which is a 597 by 3 matrix caled glen. You can load this matrix directly into you working R directory using the command load(url(&”http:/users.stat.umn.edu/~gmeden/clases/5201/datasets/glen.rda&”)) For a recent year this contains information about 597 house sales in two zip codes in St Paul. A row gives y, the sale price of a home in thousands of dollars, x, the amount of taxes paid for the house in thousands of dolars and a zip code identifier. To answer the following questions asume you know both the sales price and tax amount for every house. In each case asume that we are estimating the population mean. i) Give the true variance of the sample mean under simple random sampling without replacement for a sample of size n = 60. i) Suppose we form. three strata, the first 300, the next 200 and the final 97. Find the optimal alocation for a sample of size 60 and the true variance of this estimator. ii) Find approximately the true variance of the Ratio Estimator for a simple random of size 60. 4) For this problem you wil be using the house sales population of problem 3. In your R working directory run the following three commands > set.sed(878787) > smp1 smp2i) For smp2 give the value of the Horvitz-Thompson estimator for the population total of the house sales and its estimate of variance. denote the sale price of the ith house and xdenote the amount of taxes for the house. Consider the model . For each of the two samples find the ratio estimate of the population total and their estimates of variance. 5) For a population with a y of interest and an auxiliary x which is correlated with y and a design you need to write a program which alows you to compare the behavior. of three estimators under repeated sampling from the design. The three estimators are the Horvitz-Thompson (HT) estimator, the HT estimator that simultaneously constrains the weights so that the add to the population size and are calibrated on x, (one way to do this is explained in the R handout on the clas web page under the link calibration using quadprog) and the estimator which asumes that the design was srs with replacement and is again adjusted so that its new weights sum to the population size and are calibrated on x. For each estimator you need to compute its average value and average absolute error for 500 samples taken using the design. Apply your function to the population of house sales in problem 3) for three different designs. The designs are pps using x, using x in reverse order, i.e. in R use rev(x) and simple random sampling without replacement. Take the sample size to be n = 30. 6) Again the population of interest is the population of house sales used in problem three. In this case we are interested in estimating the median of the price of the houses sold. For 500 samples of size 30, where the sampling design is simple random sampling without replacement, find the point estimate and 95% confidence interval for the median based on the polya posterior. Also find the average absolute error of your point estimate and the frequency of coverage of your interval estimate. Next do the problem but now use pps sampling proportional to tax as your design. In this case you wil need to use the function wtpolyap that is described in the R handout usingpolyapost on the clas web page. & 本团队核心人员组成主要包括BAT一线工程师,精通德英语!我们主要业务范围是代做编程大作业、课程设计等等。我们的方向领域:window编程 数值算法 AI人工智能 金融统计 计量分析 大数据 网络编程 WEB编程 通讯编程 游戏编程多媒体linux 外挂编程 程序API图像处理 嵌入式/单片机 数据库编程 控制台 进程与线程 网络安全 汇编语言 硬件编程 软件设计 工程标准规等。其中代写编程、代写程序、代写留学生程序作业语言或工具包括但不限于以下范围:C/C++/C#代写Java代写IT代写Python代写辅导编程作业Matlab代写Haskell代写Processing代写Linux环境搭建Rust代写Data Structure Assginment 数据结构代写MIPS代写Machine Learning 作业 代写Oracle/SQL/PostgreSQL/Pig 数据库代写/代做/辅导Web开发、网站开发、网站作业ASP.NET网站开发Finance Insurace Statistics统计、回归、迭代Prolog代写Computer Computational method代做因为专业,所以值得信赖。如有需要,请加QQ:99515681 或邮箱:99515681@qq.com 微信:codehelp QQ:99515681 或邮箱:99515681@qq.com 微信:codehelp

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