STAT 200 EXAM 2 March 20, 2000 FORM BQuestions 1 - 5. An equation is determined which describes relationship between the distance (infeet) at which an individual can see a highway sign and his or her age.. The equation is Average Distance = 600 - 3 × Age .1. Estimate the distance for an individual who is 20 years old.. A. 597 B. 20 C. 11,940 D. 5402. How much does the estimated distance change when age is increased by 1? A. goes down by 1 B. goes down by 3 C. goes up by 1 D. Goes up by 33. Two people differ in age by 10 years. What is the estimated difference in the distances at whichthey can see the sign? A. 10 B. 30 C. 570 D. Can’t be determined from this informtaion4. Based on the equation, what=s the direction of the correlation between distance and age?A. Positive B. Negative C. Zero D. Direction can=t be determined5. Based on the equation, what=s the strength of the relationship between distance and age?A. There’s a strong relationshipB. There’s a weak relationshipC. There’s no relationship D. strength can=t be determined from the equationQuestions 6 –8 refer to the following plots.6. Which plot shows a relationship between for which the correlation is about 0?A. Plot A B. Plot B C. Plot C7. Which plot shows the strongest linear relationship between the two variables? A. Plot A B. Plot B C. Plot C8. In scrambled order, correlations for the three graphs are -0.9, 0 , +0.5 Which graph most appropriately matches with the correlation +0.5 ? A. Plot A B. Plot B C. Plot CPage 29. What will happen to the value of the correlation if the outlier is removed from the following plot?A. It will increaseB. B. It will decreaseC. C. It will stay the same.10. For which one of these relationships could we use a regression analysis? Only one choice iscorrect.A. Relationship between weight and heightB. Relationship between political party membership and opinion about abortionC. Relationship between gender and whether person has a tattoo. D. Relationship between eye color (blue, brown, etc.) and hair color (blond, etc.)11. The following correlation “matrix” was generatd using Minitab. The variables are height, left footlength , nose length and weight for a sample of Stat 200 students.Correlations (Pearson) Height LeftFoot NoseLeftFoot 0.319Nose 0.092 0.064Weight 0.484 0.283 0.126Which pair of variables has the weakes linear relationship?A. height and weightB. nose length and weightC. nose length and left foot lengthD. weight and left foot length12. A confidence interval will be used to estimate a proportion. For the same sample, how do thewidths of a 95% confidence interval and a 90% confidence interval compare? A. The 95% confidence interval will be wider. B. The 90% confidence interval will be wider. C. The widths of the two intervals will be the same.D. It’s impossible to know how the widths will compare.13. A recent Gallup Poll estimated that 70% of American adults are in favor of capital punishment.The margin of error for the poll was 3%. Which of the following is a 95% confidence interval for theproportion of American adults who are in favor of capital punishment?A. 64% to 76%B. 69% to 71%C. 67% to 73%D. Impossible to determine because we don’t know the sample size.Page 314. Which one of the following statements is correct?A. For 95% of all random samples from a population, the 95% confidence interval willcontain the sample proportion.B. For 95% of all random samples from a population, the 95% confidence interval willcontain the population proportion.C. For 95% of all random samples from a population, the sample proportion will equal thepopulation proportion.15. Which of the following correctly describes the relationship between pˆ and p in a problem inwhich we’re estimating a proportion?A. p is an estimate of pˆB. pˆ is an estimate of pC. pˆ and p are always equal.16. True or False? The normal curve is a good approximation to the distribution of any quantitativevariable. A. True B. False17. Suppose that in a clinical trial involving a sample of 200 individuals, 160 individuals aresuccessfully treated with a new medication. Which of the following is a 95% confidence intervalfor the proportion successfully treated with the new medication?A. 200)80.01(80.0280.0−××±B. 200)16.01(16.0216.0−××±C. 20)16.01(16.065.116.0−××±D. 200)80.01(80.0380.0−××±18. Sleep apnea is a condition of irregular breathing during sleep. Suppose that a medical researcherdetermines (based on a random sample) that a 95% confidence interval for the proportion of menwho have sleep apnea is 0.24 to 0.30. The researcher also determines that a 95% confidenceinterval for the proportion of women who have sleep apnea is 0.06 to 0.14. Based on theseconfidence intervals, which of the following is an appropriate conclusion?A. It is safe to say that the proportion with apnea is different for men than for women.B. The proportion with apnea is about the same for men and women.C. No conclusion is possible because we don’t know the sample sizesPage 419. The Gallup Poll reported the results of a survey of 625 adult employed Americans taken to assessjob satisfaction. The margin of error was reported to be 4% Which choice best describes the 4%margin of error?A. There's a 4% chance that the survey is wrong.B. There's a 95% chance that sample and population percentages differ by less than 4%C. The difference between the sample and population percentages is exactly 4%D. There's a 95% chance that sample and population percentages differ by more than 4%20. Each choice below is a factor affecting the accuracy of a survey. Only one of the choices ismeasured by the margin of error that's usually reported by the newspapers. Which factor is measuredby the "margin of error” of a survey?A. False responses by the participantsB. Inappropriate sampling frameC. Sample size (number of people in sample)D. Badly worded questions21. The Gallup Poll organization divides the country into four regions of about equal population sizeand then randomly samples 250 adults from each region. What sampling method is this?A. Volunteer B. Systematic C. Simple random D. Stratified22. The Daily Collegian conducts a poll of