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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 22 Pts 15 Pts 15 Pts 15 Pts 21 Pts 25 Pts 21 Pts 16 Pts 25 Pts 175 Pts MATH 147 FINAL EXAM Spring 2006 May 17, 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 histogram with a long right tail, the median is more than the average. 3. T F A correlation coefficient of- 1 shows a weak correlation. 4. T F The null-hypothesis assumes that an observed difference is due to chance. 5. T F If a correlation coefficient is .9 then 90% of the points are highly correlated. 6. T F If the chance of A is .6 and the chance of B is also .6, then A and B are mutually exclusive. 7. T F If two events are independent, the chance that both will happen equals the product of chances of the separate events. 8. T F For two mutually exclusive events the probability of both events occurring is the product of the individual probabilities. 9. T F Ecological correlations are based on rates of averages. They tend to overstate the strength of an association. 10. T F Selection bias was one of the reasons for the large error in the Litery Digest Poll of 1936. 11. T F If the correlation coefficient between two variables is zero ( r = 0), then there is no linear association between the variables. 1 Part II Fill in the blank For questions 12 - 16 complete the sentence by filling in the blank. (2 points for each blank) 12. Flower color in roses is controlled by one gene-pair. There are two variants of the gene, r (for red) and w (for white). The rules are: r/r makes red, r/w, w/r make pink and w/w makes white. If a r/w rose is crossed with a w/w rose, the percentage of red flowers will be ? 13. 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: , 14. 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 . 15. When drawing 4 times, without replacement, from a box containing 10 tickets, the correction factor is ....
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- Spring '07
- Math, Null hypothesis, TA, Statistical hypothesis testing, investigator, Litery Digest