Statistics 201 Practice Exam 2 From Fall 2013 This practice exam is provided solely for the purpose of familiarizing you with the format and style of the Stat 201 exams There is no explicit or implicit guarantee that the upcoming exam will ask similar questions If you use the practice exam as your only tool to help you prepare for the upcoming exam you most likely will not do well on the exam You should still do the things you would have done if you did not have access to this practice exam such as re read the text go over your class notes re work the online homework problems and look at the list of exam topics provided and make sure that you understand all the concepts listed within it Please note that the total point on this test exceed 100 This is because this practice exam has two extra questions one on Decision Trees and one from Chapter 19 to give you an idea of what was expected last semester 1 Note All problems requiring calculations should be reported to THREE decimal places unless stated otherwise 1 Gallup Inc is a researched based global performance management consulting firm whose primary business deals with public polling of residents of the U S and other countries around the world In 2012 a Gallup Poll asked Do you believe that illegal immigration is an issue in the United States of America Gallup s final report stated Results are based on telephone interviews conducted in the year 2012 with a simple random sample of 210 014 adults aged 18 and older living in the contiguous adjoining 48 states of the U S Sixty three percent of the contacted respondents believe that illegal immigration is a huge problem in the United States Use this information to answer the following questions below a 3 points What is the population of interest for this poll b 3 points What is the parameter of interest for this Gallup poll c 2 points What is the sample d 2 points Although Gallup performed a simple random sample adults for this poll is there any potential segment of the population do you believe were omitted Explain if applicable the potential portion of the adult U S population that was undercovered or not fully represented in the simple random sample that Gallup performed 2 2 An insurance company wanted to understand the relationship between the age of their policy holders and the number of claims filed by them A large number of policy holders were sampled and a linear regression model was fit to the data that were collected Only the policy holders themselves were used in the analysis i e spouses and dependents ages and claims were not included in the analysis The age in years of the policy holder and the number of claims filed for that policy holder in the last 12 months were used in the analysis The following equation resulted i 3 points Provide a brief interpretation for the value of the slope of this regression equation ii 3 points Do you believe the y intercept has any logical interpretation in this case Circle one YES NO If you circled YES provide your interpretation below If you circled NO why do you believe there is no logical interpretation for the y intercept in this case iii 3 points Use the regression equation above to estimate the number of claims a 55 year old policy holder will make in a year 3 3 Recent data from a Tennessee voting district show that about 45 of this district s registered voters are Republicans 40 are Democrats 11 are Tea Party affiliates and 4 are Other Assume that a voter can only be registered with one affiliation i e a voter cannot be a registered member of the Tea Party and a member of the Republican Party Report your answers to FOUR decimal places i 2 points What is the probability that a randomly selected registered voter from this district is either a Democrat or Other ii 2 points Suppose that Event A is that a randomly selected registered voter from this TN district is a Republican What is the probability of Event A s complement iii 3 points Suppose two randomly selected registered voters from this TN district are asked their voter registration party What is the probability that they both are Democrats iv 3 points Suppose you poll five random registered voters from this district What is the probability that at least one of them is a democrat v 2 points Harry and Sally are married and live in this Tennessee voting district Should you use the multiplication rule of probability to determine the probability that both Harry and Sally are Republicans Circle your answer Yes No Briefly defend your circled response 4 4 Hospitals like many organizations are interested in obtaining certain information from its employees Suppose that the administration of a large metropolitan hospital is interested in obtaining feedback from its employees regarding a myriad of issues ranging from their daily stress levels at work to how certain hospital procedures and processes can be improved The hospital administration has employed an independent analyst to create a questionnaire along with various sampling schemes in order to garner feedback on these issues For each of the following match the appropriate sampling method with the scenarios below 2 points each The analyst identifies six categories of employees administration physicians nurses medical technologists clerical and maintenance From the six categories he randomly selects 50 individuals from each category and gives them the questionnaire He then combines the results and relays the results to the interested party Each employee has a unique identification number The analyst uses a random number generator to attach a whole integer to each ID number he sorts the random numbers in ascending order The first 250 employees listed receive the questionnaire At the hospital cafeteria the analyst selects every fifth person who enters on a specific day beginning with the tenth person who walks through the door A link to the questionnaire is included in the email that all employees receive when their paycheck is ready All employees are asked to participate in the on line questionnaire and the employees who respond are analyzed a b c d e f g Convenience Sample Cluster Sample Simple Random Sample Multistage Sample Stratified Sample Voluntary Response Sample Systematic Sample 5 The University of Tennessee Parking Services reports that 35 of UT students buy a commuter parking permit every year Suppose we randomly pick 100 UT students from the University Registrar database Let represent the proportion of students in this
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