Stats 10 - Midterm 1 Spring 2014VERSION 2NAME:SECTION:Academic Misconduct:• Any potential violation of UCLA’s policy on academic integrity will be reported to the officeof the Dean of Students. All work on this exam must be your own.Multiple Choice• On your Scantron sheet write your name, ID, lecture and section letter and TEST Version (fill in thebubbles).• Enter all answers on the scantron sheet (those not recorded on the scantron will NOT be graded).• Choose only ONE answer for each question.• No partial credit will be given for multiple choice.Calculators• You may use a calculator, but you may NOT share with your neighbor.• Cell phones, iPods or other Internet connected devices are NOT allowed to be used as calculators.Other Test Instructions• You are allowed note sheet (8.5 x 11”) with writing on BOTH sides.• Show all your work for the open ended question in order to get credit.• Write clearly. Short answers are best.GOOD LUCK!Biomedical researchers at Duke University recently received FDA approval to study the effects of aspirin onblood circulation of recent heart surgery patients. Their main goal is to see if daily consumption of aspirincauses the human heart to move blood more efficiently throughout the body. The scientists have a group of100 patients who have had a heart surgery in the last month. The scientists randomly assign patients to threegroups: group 1 receives two placebo sugar pills, group 2 receives two 100 mg tablets of aspirin and group 3receives two 200 mg tablets of aspirin. All the placebos and tablets are the same size. The scientists knowwhich group each patient is in. After 6 months, the scientists measure the blood circulation efficiency of eachpatient and tests to see if there are significant differences between each of the 3 groups. Use this informationfor questions 1 and 2.1. If the researchers find that groups 2 and 3 each have significantly better blood circulation than group 1.They can conclude that:(a) Aspirin causes better blood circulation in these recent heart surgery patients.(b) Aspirin consumption is only associated with better blood circulation in these recent heart surgerypatients.(c) They cannot conclude anything about aspirin because of possible confounding variables.2. This is an example of a:(a) A double-blinded experiment.(b) A single-blinded experiment(c) A no-blinded study.(d) The placebo effect.3. Wildlife researchers monitor the length and weight of the local alligator population. The mean weight ofthe alligator population is 645 lbs with a standard deviation of 124 lbs and the mean length is 130 incheswith a standard deviation of 16 inches. The R2for the positive relationship between the variables is 0.772.What is slope of the linear regression line to predict alligators weight in pounds from its length in inches.(a) 0.113(b) 4.359(c) 5.983(d) 6.8094. MENSA is an organization whose members claim to have IQs in the top 2.5% of the population. If IQs areunimodal, symmetric, and mound-shaped with mean 100 and standard deviation 16 what is the minimumIQ score required for admission into MENSA. Choose the closest answer.(a) 116(b) 132(c) 140(d) 13625. People’s IQs are unimodal, symmetric, and mound-shaped with mean 100 and standard deviation 16.Using the empirical rule, which of the following is true for the percentage of people with IQs between 84and 100 in relation to the percentage of people between 49 and 84.(a) The percentage of people with IQs between 84 and 100 is smaller than the percentage of people withIQs between 49 and 84.(b) The percentage of people with IQs between 84 and 100 is larger than the percentage of people withIQs between 49 and 84.(c) The percentage of people with IQs between 84 and 100 is equal to the percentage of people with IQsbetween 49 and 84.(d) Cannot make any conclusions about the percentage of people within each of these groups.6. What would be the slope between the annual salaries of males and females at a company if for a certaintype of position women always made 5% less than men?(a) 0.95(b) 0.05(c) 1(d) -17. Given two sets of numbers which has the larger standard deviation?set A: 327, 346, 327, 323, 347, 304, 301, 326, 372, 327set B: 19, -4, 20, -23, -26, 0, 0, -1, 0, 45(a) Set A(b) Set B(c) They are equal.(d) Can’t tell.8. Given any dataset of any two numbers which of the following is not a possible value for the standarddeviation?(a) 0(b) -1(c) 1(d) 1 billion!9. If the square point in the upper left hand corner of the scatterplot is removed from the dataset what willhappen to the slope of the line or best fit and the correlation (r)?(a) Both will increase.(b) Both will decrease.(c) Slope will increase, r will decrease.(d) Slope will decrease, r will increase.3Over the past decade, Americans have clustered into three broad groups based on the answers to a series of questionon global warming: “Concerned Believers” – those who attribute global warming to human actions and are worriedabout it, followed by the “Mixed Middle,” and the “Cool Skeptics” – those who are not worried about globalwarming much or at all Results of Gallup poll from telephone interviews conducted March 6-9, 2014, on with arandom sample of 625 adults, aged 18 and older, living in all 50 U.S. states and the District of Columbia. Answerquestions 10 through 13 using this information and the following contingency table.Male FemaleConcerned Believer 74 88Mixed Middle 162 162Cool Skeptic 99 4010. What type of study is this?(a) Observational study(b) Single-blind experiment(c) Double-blind experiment11. What percent of female adults surveyed were Cool Skeptics?(a) 6.4%(b) 28.8%(c) 54.3%(d) 13.8%12. What percent of adults surveyed were males and Concerned Believers?(a) 11.8%(b) 22.1%(c) 45.6%(d) 28.4%13. Is there an association between gender and belief in global warming?(a) No. The proportion of Concerned Believers, Mixed Middle, and Cool Skeptics are equal with respect to gender.(b) Yes. The proportion of Concerned Believers, Mixed Middle, and Cool Skeptics are equal with respect togender.(c) Yes. There is a higher proportion of both Concerned Believers and Mixed Middle amongst females thanamongst males.(d) No. There is a higher proportion of both Concerned Believers and Mixed Middle amongst females thanamongst males.14. For the regular season Los Angeles Clippers star Blake Griffin averaged 24.1 points per game with a standarddeviation of 3.3 points per game. This past Monday he scored