STAT 302 Section 503Fall 2017Exam #2PracticeInstructor: Raanju SundararajanName:1. DO NOT open this until you are told to do so.2. You need a 8.5 × 11” GRAY scantron, pencil, calculator and you may have one page as a tip sheet(formula sheet).3. There are 16 multiple-choice questions on this exam, each worth 5 points. There is NO partial credit. Please markyour answers clearly. Multiple marks will be counted wrong.4. You will have 60 minutes to finish this exam.5. If you are caught cheating or helping someone to cheat on this exam, you both will receive a grade of zero on theexam. You must work alone.6. When you are finished please make sure you have filled in your name and marked your FORM (A or B) and 16answers, then turn in JUST your scantron.7. All the very best!ANSWERS: 1E, 2D, 3D, 4C, 5C, 6A, 7A, 8B, 9D, 10C, 11C, 12B, 13C, 14B, 15A, 16D1STAT 302 sec 503 Exam #2, Practice Fall 20171. Japan produces some of the fastest trains in our planet.Suppose that we are interested in testing whether theaverage speed of the Shinkansen(the high speed railwayof Japan) is more than 400km/hr. Describe the TypeII error.A. Stating that the speed was higher on an averagethan 400km/hr when in reality it was not.B. Stating that the speed was higher on an averagethan 400km/hr when in reality it was higher than400.C. Stating that there was statistically significant ev-idence that the speed was higher on an averagethan 400km/hr when in reality it was higher.D. Stating that there was no statistically significantevidence that the speed was higher on an averagethan 400km/hr when in reality it was not higher.E. Stating that there was no statistically significantevidence that the speed was higher on an averagethan 400km/hr when in reality it was higher.2. What is the best interpretation of a 95% confidenceinterval for a proportion given by (0.0178, 0.499)?A. 95% of the time, in repeated sampling from thesame population, the true proportion, p, will bepositive since this interval only contains positivevalues.B. The probability of getting a positive true propor-tion, p, is 95%.C. If we repeatedly sampled the same population, wewould get positive intervals like this one 95% ofthe time.D. If we repeatedly sampled the same population, wewould be 95% confident that all of our intervalswould contain the true proportion, p.E. Two of the above are correct interpretations.3. Hypothesis testing meansA. Constructing estimates of the population parame-ters by framing statements.B. Testing for the unbiasedness of sample estimates.C. Testing for the distributional assumption of astatistic.D. Testing for the correctness of an assertion concern-ing a population parameter.E. None of the above are true.4. The General Social Survey included a question abouthow many hours the respondent spent doing religiousactivities outside of their own home. For the 1,414respondents the sample mean was 6.15 hours and thepopulation standard deviation was 16.53 hours. Findthe 95% confidence interval for the population meanamount of time spent doing religious activities outsideof their own home.A. (5.43, 6.87)B. (-26.24, 38.55)C. (5.29, 7.01)D. (5.03, 7.27)E. None of the above.5. Which of the following is true about the margin of errorin a confidence interval?A. It accounts for the error due to an absence of ran-domization during sampling.B. It accounts for the error caused by the presence oflurking variables.C. It accounts for the error caused by using a samplewhose size is smaller than the entire population.D. It accounts for the error caused by an incorrectdistributional assumption on the estimator.E. Two of the above 4 statements are true.6. Suppose, in a test of hypotheses problem for a normally-distributed variable with population mean , we want totest H0: µ = 21.58, H1: µ < 21.58. We have a sampleof 25 observations with sample mean 20.62 and samplevariance 5.42. Calculate the p-value for this test.A. 0.025B. 0.975C. 0.050D. 0.50E. 0.0407. Suppose that you are a writer for a university newspa-per and due to time constraints you conduct a surveyof only 20 randomly selected students. You ask them,”Do you plan to watch the Rockets game this week-end?” and 19 of them say they plan to watch. Create a95% confidence interval for the proportion of studentsthat plan on watching the game.A. (0.84, 1)B. (0.74, 1)C. (0.76, 0.99)D. (0.44, 0.68)E. Cannot be determined.8. If 37% of the American population has blood type O+,what is the probability that more than 420 out of thenext 1000 randomly sampled Americans will have bloodtype O+?A. 0.9995B. 0.0005C. 0.95D. 0.05E. None of the above.2STAT 302 sec 503 Exam #2, Practice Fall 20179. A team of researchers wished to study whether oatmealreduced bad cholesterol levels in those who ate it. Theyfound 500 adults over age 40 who regularly eat oatmealor products from oatmeal. They then matched each ofthese 500 with a similar adult (one of the same gender,within 10 pounds of the same weight, and who exer-cised roughly the same amount) who did not regularlyeat oatmeal or products made from oatmeal. Finally,they measured the bad cholesterol LDL for each adultand compared both groups. The above is NOT an ex-periment becauseA. It did not use a random sample of subjects.B. It used matched pairs.C. It was not randomized.D. The researcher did not control whether the adultsregularly ate oatmeal or not.E. None of the above.10. The survival times of guinea pigs inoculated with aninfectious viral strain vary from animal to animal. Thedistribution of survival times is strongly skewed to theright. The central limit theorem says that:A. as we study more and more infected guinea pigs,their average survival time gets even closer to themean m for all infected guinea pigs.B. the average survival time of a large number of in-fected guinea pigs has a distribution of the sameshape (strongly skewed) as the distribution for in-dividual infected guinea pigs.C. the average survival time of a large number of in-fected guinea pigs has a distribution that is closeto a Normal distribution.D. the average survival time of a large number of in-fected guinea pigs has a distribution that is closeto a t-distribution.E. None of the above.11. Are Nano iPods more reliable than the early version,Mini iPods? Which set of hypotheses would we use totest this given that the π’s are the percent FAILUREfor each model?A. H0: πN ano− πM ini= 0 vs. HA: πN ano6= πM iniB. H0: πN ano− πM ini= 0 vs. HA: πN ano> πM iniC. H0: πN ano−