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Unformatted text preview: Page 1 Page 2 Page 3 Page 4 Page 5 Page 6 Page 7 Page 8 Page 9 Total 20 Pts 20 Pts 12 Pts 15 Pts 15 Pts 14 Pts 25 Pts 21 Pts 30 Pts 172 Pts MATH 147 FINAL EXAM Fall 2006 December 13, 2006 Name: Section: DIRECTIONS: Show all work. Solutions with no work will receive NO credit. Neatness counts. All necessary tables are provided at the end of the test. Carry out all your calculations to at least two digits to the right of the decimal point. Part I True/False For questions 1 - 11 circle T for true and F for false. (2 points each) 1. T F In an observational study, the effects of treatment may be confounded with the effects of factors that got the subjects into the treatment or control group in the first place. 2. T F In a series of repeated measurements, bias can easily be detected by looking at the long run average of the measurements. 3. T F If you perform above average on an exam and you have an even better performance on the next exam, your overall performance on these two tests can be explained by the regression effect. 4. T F A correlation coefficient of- 1 shows a weak correlation. 5. T F If the chance of A is .6 and the chance of B is also .6, then A and B are mutually exclusive. 6. T F If two events are independent, the chance that both will happen equals the product of chances of the separate events. 7. T F In 1990, four passengers were killed by crashes on commuter airlines, compared to 39 killed on scheduled carriers (like United, Delta, and so forth). These data show that if you decide to fly, it is safer to do so on a commuter airline. 8. T F Ecological correlations are based on rates of averages. They tend to overstate the strength of an association. 9. T F When sampling from a population, the method of choosing a sample does not matter if the sample size is large. 10. T F If a difference is highly significant there is less than a 1% chance for the null hypothesis to be true. 1 11. T F In a controlled experiment, the subjects decide whether they are assigned to the treatment group or the control group. Part II Fill in the blank For questions 12 - 20 complete the sentence by filling in the blank. (2 points for each blank) 12. A certain SAT Exam has an average score of 600 and a SD of 100. The score that best approximates the 20 th percentile is . 13. The slope of the equation of the line passing through the points (1, 0) and (4, 2) is . 14. A box contains three tickets with a 0 and five tickets with a 1. Eighty draws are made at random with replacement. There are 47 1’s among the draws. The chance error is and the SE is . 15. An investigator collects data on hourly wage rates for three groups of workers. Workers in group B earn about twice as much as those in group A; workers in group C earn about $10 an hour more than those in group A. In the blank indicate which histogram corresponds to Group A: , 16. Two variables have a correlation coefficient of r = 0 . 5. If each of the data items of the first variable are multiplied by 2, the resulting correlation coefficient is...
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- Fall '07
- Math, Statistical hypothesis testing, Simple random sample