STAT 302 Section 503 Fall 2017 Exam 2 Practice Instructor Raanju Sundararajan Name 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 mark your 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 the exam 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 16 answers 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 16D 1 STAT 302 sec 503 Exam 2 Practice 1 Japan produces some of the fastest trains in our planet B 26 24 38 55 Suppose that we are interested in testing whether the C 5 29 7 01 average speed of the Shinkansen the high speed railway D 5 03 7 27 of Japan is more than 400km hr Describe the Type II error E None of the above Fall 2017 A Stating that the speed was higher on an average than 400km hr when in reality it was not 5 Which of the following is true about the margin of error in a confidence interval B Stating that the speed was higher on an average than 400km hr when in reality it was higher than 400 A It accounts for the error due to an absence of randomization during sampling C Stating that there was statistically significant evidence that the speed was higher on an average than 400km hr when in reality it was higher B It accounts for the error caused by the presence of lurking variables C It accounts for the error caused by using a sample whose size is smaller than the entire population D Stating that there was no statistically significant evidence that the speed was higher on an average than 400km hr when in reality it was not higher D It accounts for the error caused by an incorrect distributional assumption on the estimator E Stating that there was no statistically significant evidence that the speed was higher on an average than 400km hr when in reality it was higher E Two of the above 4 statements are true 6 Suppose in a test of hypotheses problem for a normallydistributed variable with population mean we want to test H0 21 58 H1 21 58 We have a sample of 25 observations with sample mean 20 62 and sample variance 5 42 Calculate the p value for this test 2 What is the best interpretation of a 95 confidence interval for a proportion given by 0 0178 0 499 A 95 of the time in repeated sampling from the same population the true proportion p will be positive since this interval only contains positive values B The probability of getting a positive true proportion p is 95 C If we repeatedly sampled the same population we would get positive intervals like this one 95 of the time D If we repeatedly sampled the same population we would be 95 confident that all of our intervals would contain the true proportion p E Two of the above are correct interpretations A B C D E 0 025 0 975 0 050 0 50 0 040 7 Suppose that you are a writer for a university newspaper and due to time constraints you conduct a survey of only 20 randomly selected students You ask them Do you plan to watch the Rockets game this weekend and 19 of them say they plan to watch Create a 95 confidence interval for the proportion of students that plan on watching the game 3 Hypothesis testing means A Constructing estimates of the population parameters by framing statements A 0 84 1 B Testing for the unbiasedness of sample estimates B 0 74 1 C Testing for the distributional assumption of a statistic C 0 76 0 99 D 0 44 0 68 D Testing for the correctness of an assertion concerning a population parameter 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 the next 1000 randomly sampled Americans will have blood type O E None of the above are true 4 The General Social Survey included a question about how many hours the respondent spent doing religious activities outside of their own home For the 1 414 respondents the sample mean was 6 15 hours and the population standard deviation was 16 53 hours Find the 95 confidence interval for the population mean amount of time spent doing religious activities outside of their own home A 0 9995 B 0 0005 C 0 95 D 0 05 E None of the above A 5 43 6 87 2 STAT 302 sec 503 Exam 2 Practice Fall 2017 9 A team of researchers wished to study whether oatmeal B The parameter of interest is the population mean reduced bad cholesterol levels in those who ate it They work in hours for men found 500 adults over age 40 who regularly eat oatmeal C The parameter of interest is the maximum number or products from oatmeal They then matched each of of hours worked in a week these 500 with a similar adult one of the same gender D The parameter of interest is the minimum number within 10 pounds of the same weight and who exerof hours worked in a week cised roughly the same amount who did not regularly E None of the above eat oatmeal or products made from oatmeal Finally they measured the bad cholesterol LDL for each adult and compared both groups The above is NOT an ex 13 Suppose that you are interested in determining how many days Americans spend on vacation Your friend periment because thinks that it is 7 days while you think that it is higher than that You take a simple random sample of 20 peoA It did not use a random sample of subjects ple The sample mean is 8 2 and the standard deviation B It used matched pairs is 2 4 Find the test statistic C It was not randomized A 2 57 D The researcher did not control whether the adults B 1 96 regularly ate oatmeal or not C 2 24 E None of the above D 2 24 E 2 57 10 The survival times of guinea pigs inoculated with an infectious viral strain vary from animal to animal The distribution of survival times is strongly skewed to the right The central limit theorem says that 14 Has there been a significant change in the proportion of Americans that believe that we are spending too little on improving the education …