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Question;It is given that;for;the expenses of books and supplies for the students of a certain large;university for a semester. To estimate the mean of such expenses for all the;students, a simple random sample of 35 students is taken and the mean for these;35 students is.;1. What;is the margin of error of your estimate of the population mean at a 95%;confidence level?;2. Construct;a 95% confidence interval for the mean such expenses for all the students.;3. What;is the margin of error of your estimate of the population mean at a 99%;confidence level?;4. Construct;a 99% confidence interval for the mean such expenses for all the students.;5. Which;of the two confidence interval is wider?;Consider;the following for the questions 6-9;We;have to construct a confidence interval for the mean of SAT (verbal and;quantitative) scores of students who use a special coaching. How large a sample;must be taken to participate in the coaching group to estimate this mean with a;margin of error of no more than 25 points if we can assume that the population;standard deviation is 175 points for the reference population?;Compute the required sample size for each;of the following confidence levels.;6. 90%;confidence;7. 95%;confidence;8. 99%;confidence;Consider;the following for the questions 10-12;A clinic claims that the average time taken;by a patient to see the doctor from the appointment time;is 30 minutes. A simple random sample of 35;patients is contacted the mean of the wait time for this sample is 47 minutes;and the standard deviation of the wait time for;this sample is 12 minutes.;10.What;is the margin of error of your estimate of the population mean at a 95%;confidence level?;11.Construct;a 95% confidence interval for the mean wait time for all the patients.;12. Is;30 minute in this interval?;Consider;the following for the questions 13-15;In a simple random sample of 821 citizens;63% said that they approve the tax raise for improving the infra-structure of;the nation.;13.What;is the margin of error of your estimate of the population proportion at a 95%;confidence level?;14.Construct;a 95% confidence interval for the proportion of all the people who approve the;tax raise for improving the infra-structure of the nation.;15.How;large a sample should be taken to estimate this proportion with 95% confidence;with a margin of error of no more than 2% points.;Use the following for the questions 16-18;The mean weight of the adults in a certain;region is believed to be. An agency thinks that this;mean may be higher than;the above belief. They are going to take a simple random sample of 100 adults;for a hypothesis test at 5% level of significance.;16.State;the null and the alternate hypothesis for this test.;17.If the mean weight of the;adults in the above simple random sample is and we know that the;population standard deviation is,compute the test statistic and the P_value of the test.;18.Will you reject or not reject the null hypothesis at 5% level;of significance?;Use the following for questions 19-22;An expensive;medication from a particular company states 100 ml for the contents on the;bottles for this medication. An agency would like to test if the bottles are;being under filled, in the sense that the mean contents of all bottles is less;than 100 ml.;19.State the null;hypothesis and the alternative hypothesis.;20. The;contents in 10 randomly selected bottles were measured, and the results are;below in ml.;contents in ml;96.0;102.0 99.4 100.5;97.5 98.7 103.4;97.6 98.5 99.4;Variable N;N* Mean SE Mean;StDev Minimum Q1;Median Q3;contents 10;0 99.300 0.696;2.201 96.000 97.575;99.050 100.875;Variable Maximum;contents 103.400;State the test statistic;21.State;the P_value.;22.Does;this sample show a good evidence at 5% level of significance that the bottles;are being under filled?;Use the following for the questions 23-28;The electricity supply in a certain region;appears to show a lot of voltage fluctuation from the required value of 240 V.;To check if the mean voltage is different;from 240 V, the voltage will be measured at 15 randomly selected times.;23.State the null and;the alternative hypothesis for this test.;24.The;following are the readings shown by the 15 measurements.;voltage;222.2 217.9 211.9;219.7 208.8 229.5;219.4 208.1 209.0 208.2;196.2 211.7 199.9;201.1 218.0;Variable N;N* Mean SE Mean;StDev Minimum Q1;Median Q3;voltage 15;0 212.11 2.35;9.10 196.20 208.10;211.70 219.40;Variable Maximum;voltage 229.50;Write the test;statistic.;25.Will you reject or;not reject the null hypothesis at 5% level of significance?;26.Compute;a 95% confidence interval for the overall mean voltage based on the results;from the above sample.;27.Does;this interval contain the value 240 Volt?;28.Explain;the usage of a 95% confidence interval for a two sided hypothesis test for a;population mean at a 5% level of significance.;Use the following for the questions 29-30;In;the past, 44% of those taking a public accounting qualifying exam have passed;the exam on their first try. Lately, the availability of exam preparation books;and tutoring sessions may have improved the likelihood of an individual?s passing;on his or her first try. To test if the likelihood of passing in the first try;in now higher;a;simple random sample of recent applicants will be examined.;29.State the null;hypothesis and the alternative hypothesis;30. In a;sample of 250 recent applicants, 130 passed on their first attempt. At 0.05 level;of significance, can we conclude that the proportion passing on the first try;has increased? State the P_value and a;reason for your conclusion.;31.In about 100 words, explain to a person what;does standard deviation mean.;You;do not have to write the formula, write in terms of a real world application.;32.In about 100 words, explain the meaning of;P_value in the context of hypothesis test.;You;may use an example from the book or any other resource.;Please;make sure to understand your post and give the reference of the resource if you;are using any.

 

Paper#61785 | Written in 18-Jul-2015

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