Psychics: 5% 38% -28% 8% -3%DS350 – QUANTITATIVE METHODS FOR BUSINESS DECISIONSFALL SEMESTER 2003“Wonderful Joyous Time” #2Answer the following questions in the space provided. Show your work as appropriate. Relativeproblem weights are given in brackets; these total 100 points. Unless the problem indicatesotherwise, use the traditional confidence level of 95% and the traditional significance level of=.05. The word “Pledged” in front of your signature on this “quiz” shows your ongoingaffirmation to the Stetson Honor System.Question 1 [4 points]:Find the sample standard deviation for the following data:8126.59 3202.74 9718.58 4221.92 3089.44 4228.56 1129.33[Hint: Use the built-in function on your calculator. If you don’t know how that function works, save this problem for last.]Question 2 [10 points; 2 each part]:Indicate whether each of the following statements is TRUE or FALSE.a) The Literary Digest’s very large sample size allowed it accurately to predict the 1936 Presidential election. TRUE FALSEb) All else being equal, a 92% confidence interval will be wider than an88% confidence interval. TRUE FALSEc) Chi-square tests are used with hypotheses involving several means. TRUE FALSEd) Convicting an innocent person is an example of a Type I error. TRUE FALSEe) Generally speaking, data quality is better with prospective rather thanretrospective observational studies. TRUE FALSEQuestion 3 [4 points]:Gracetta Squornshellous is conducting a market research study. She wants to know whether solar powered flashlights sell better when they’re packaged in a fuchsia box or a mauve box. She recruits ten retail stores to participate in the study. Five (randomly chosen) are stockedwith solar powered flashlights in fuchsia boxes; the rest get the mauve boxes. She collects data on how many flashlights each store sells. What test should Gracetta use in analyzing her data?_____ independent sample test on means _____ paired data test on means_____ independent sample test on proportions _____ paired data test on proportions_____ chi-square test _____ none of theseQuestion 4 [4 points]:Mortimer Snodgrass wonders whether basketweaving majors or recreation majors at the University of Southern North Dakota at Hoople are less likely to find a job upon graduation. This is a very important question for Mortimer – since he is trying hard to avoid gainful employment. Hence he decides to survey every single basketweaving major (all 42 of them) andevery single recreation major (also 42 of them) who graduated last year. What test should he use in analyzing his data?_____ independent sample test on means _____ paired data test on means_____ independent sample test on proportions _____ paired data test on proportions_____ chi-square test _____ none of theseQuestion 5 [4 points]:Balph Snerdwell wants to know whether students in Dr. Rasp’s statistics classes are more likely to get a good night’s sleep the night before a “big quiz,” or to harbor homicidal thoughts toward the instructor. He asks ten of his classmates whether they got lots of sleep, and whether they had murderous thoughts. (And yes, it is possible to do both. It makes for interesting dreams.) What test should he use in analyzing his data?_____ independent sample test on means _____ paired data test on means_____ independent sample test on proportions _____ paired data test on proportions_____ chi-square test _____ none of theseQuestion 6 [4 points]:Five Stetson University students are sampled at random, and asked how many statistics classes they plan to take. The data are: 2, 0, 5, 1, 2. What is  (the population standard deviation) in this situation?_____ 2 _____ 7 _____ √2 _____ √7 _____ 42_____ We can’t tell from the information given.Question 7 [4 points]:Leonore Overture is conducting a hypothesis test to investigate whether listening to classical music improves intelligence. She gets a p-value of .0000000000000000042. What conclusion does she draw?_____ There is not enough evidence to believe that classical music makes you smart._____ There is not enough evidence to believe that classical music has no effect._____ There is enough evidence to believe that classical music makes you smart._____ There is enough evidence to believe that classical music has no effect.Question 8 [4 points]:Clyde Arthur Fazenbaker is conducting a hypothesis test to determine whether a coin is fair. He has computed a test statistic of 0. What does that imply?_____ He got the same number of “heads” as “tails.”_____ He made a computational mistake, since a test statistic cannot be 0._____ His null hypothesis is false._____ He made a Type I error.Question 9 [4 points]:George Herbert Shrub is testing to see whether broccoli causes cancer. What would a Type I error be in this situation?Question 10 [4 points]:Alphonso Ferrabosco II is conducting a survey on student opinion regarding having intercollegiate football at Stetson. He distributed over 200 surveys. He does so at a variety of locations around campus – Commons, several classroom buildings, the Hollis Center, some campus parking lots – in an attempt to get a good cross-section of the student body. Does Alphonso have a random sample? Explain.Question 11 [30 points, divided as indicated]:Clorinda Cragdingle is beginning a program of personal investing, and wants to know whether to take advice from stockbrokers or psychics. One month ago she contacted five stockbrokers and asked for one stock pick from each. She also made five phone calls to the Psychic Friends Network (Motto: “I knew you were going to call.”), again asking for one stock pick from each. The returns for the month have been as follows:Stockbrokers: 42% 10% -30% 17% -14%Psychics: 5% 38% -28% 8% -3%a) [4] Clorinda has a {PICK ONE} _____ prospective study _____ retrospective studyb) [4] Clorinda has {PICK ONE} _____ paired data _____ independent samplesc) [6] State Clorinda’s null and alternative hypotheses, in words and in symbols.d) [8] Compute an appropriate test statistic. Give the p-value of the test.e) [2] This is a: ____ z _____ t _____ 2 . It has ________ degrees of freedom (if appropriate) f) [6] State an appropriate conclusion, both in statistics jargon (reject/don’t reject) and in the context of the problem.Question 12 [26 points, divided as indicated]:Does cell phone use cause brain damage? Fifty rats are used in a