Stat/For/Hort 571: December 16, 1998 Final Exam - Statistics, Exams of Data Analysis & Statistical Methods

Download Stat/For/Hort 571: December 16, 1998 Final Exam - Statistics and more Exams Data Analysis & Statistical Methods in PDF only on Docsity! Stat/For/Hort 571 Chuang and Nordheim December 16, 1998 Final Name: For the section that you attend please indicate: Instructor:(circle one) Chuang Nordheim TA: (circle one) Cong Li Zou Instructions: 1. This exam is open book. You may use textbooks, notebooks, class notes, and a calculator. 2. Do all your work in the spaces provided. If you need additional space, use the back of the preceding page, indicating clearly that you have done so. 3. To get full credit, you must show your work. Partial credit will be awarded. 4. Note that some questions have multiple parts. For some questions, these parts are independent, and so you can work on part (b) or (c) separately from part (a). 5. Some partial computations have been provided on some questions. You may find some but not necessarily all of these computations useful. You may assume that these computations are correct. 6. Do not dwell too long on any one question. Answer as many questions as you can. For graders’ use: Question Possible Points Score 1 20 2 20 3 20 4 20 5 20 Total 100 1. An experiment was conducted on the effects of different sugars on the length of pea sections grown in culture. Seven (random) petri plates were used for each of the 4 treatments. The treatments with sample means and standard deviations are given below: control +glucose +fructose +sucrose ȳ 68.6 55.7 56.4 64.0 s 6.9 6.3 7.4 5.7 (a) Test the null hypothesis that the population means are the same for all 4 treatments. Interpret the results. (Note SSTrt = 811.21 and SSErr = 1047.30.) (b) Find a 95% confidence interval for the difference between the average of the 3 sugar treatments and the control treatment. Interpret the results. (c) Compare all pairs of means using the LSD method with a comparison-wise error rate of 0.05. (Use the form of display given in class.) 2. An experiment was undertaken to determine the effect of relative humidity on the weight loss of beetles subject to 5 days of starvation. At each value of relative humidity, a fixed number of randomly selected beetles were placed in a container. The combined weight loss of all the beetles in each container was recorded in mg. The following data were obtained. xi relative humidity 0 15 30 45 60 75 yi weight loss 9.4 7.6 6.5 6.5 5.0 4.1∑ xi = 225 ∑ yi = 39.1 ∑ x2i = 12375 ∑ y2i = 272.43 ∑ xiyi = 1209. 1