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Fall Semester Final Exam 2012 Review #2 Name: __________________________ Date: _____________ ___ 1. Shade the area under the standard normal curve corresponding to the probability below. P ( –2 ≤ z ≤ 1) A) B) C) Statistics - Ms. Metheny Page 1 Fall Semester Final Exam 2012 Review #2 D) E) ___ 2. You draw two cards from a standard deck of 52 cards and do not replace the first one before drawing the second. Find the probability of drawing a 7 and a 9 in either order. Round your answer to the nearest thousandth. A) 0.078 B) 0.012 C) 0.037 D) 0.311 E) 0.013 ___ 3. The college hiking club is having a fund raiser to buy new equipment for fall and winter outings. The club is selling Chinese fortune cookies at a price of $3 per cookie. Each cookie contains a piece of paper with a different number written on it. A random drawing will determine which number is the winner of a dinner for two at a local Chinese restaurant. The dinner is valued at $34. Since fortune cookies are donated to the club, we can ignore the cost of the cookies. The club sold 725 cookies before the drawing. Lisa bought 30 cookies. The probability she will win the dinner for two 6 .What is the probability she will not win the dinner for two? Write your answer as a fraction is 145 in simplest form, if one exists. 6 1 6 139 A) B) C) D) E) none of these choices 139 30 145 145 Statistics - Ms. Metheny Page 2 Fall Semester Final Exam 2012 Review #2 ___ 4. Finish times (to the nearest hour) for 57 dogsled teams are shown below. Make a dotplot for the data. 261 271 236 244 279 296 284 299 350 288 247 256 308 360 341 333 261 266 287 296 313 311 307 330 299 303 277 283 304 305 350 290 350 289 297 299 332 330 309 328 330 328 285 291 295 298 306 315 310 318 318 318 333 321 323 324 327 A) B) C) D) E) none of these choices Statistics - Ms. Metheny Page 3 Fall Semester Final Exam 2012 Review #2 ___ 5. Find the sample standard deviation s for the following sample data. Round your answer to the nearest hundredth. x: 24 19 13 31 26 A) 6.88 B) 8.35 C) 9.34 D) 6.15 E) 8.16 ___ 6. Richard has been given a 12-question multiple-choice quiz in his history class. Each question has three answers, of which only one is correct. Since Richard has not attended the class recently, he doesn't know any of the answers. The success occurs if Richard answers a question correctly and the failure occurs if Richard is unable to answer a question correctly. Assuming that Richard guesses on all 12 questions, find the probability that he will answer at least 7 questions correctly? Round your answer to the nearest thousandth. A) 0.048 B) 0.500 C) 0.583 D) 0.194 E) 0.066 ___ 7. Data may be classified by one of the four levels of measurement. What is the name of the highest level? A) interval B) nominal C) ordinal D) ratio E) simple ___ 8. A coin is to be tossed 1000 times. What is the probability that the 785th toss is heads? A) 0 B) 1/4 C) 1/2 D) 3/4 E) 1 ___ 9. Assume that about 40% of all U.S. adults try to pad their insurance claims. Suppose that you are the director of an insurance adjustment office. Your office has just received 132 insurance claims to be processed in the next few days. What is the probability that fewer than 51 of the claims have been padded? A) 0.591 B) 0.409 C) 0.375 D) 0.625 E) 0.341 ___ 10. Let x be the average number of employees in a group health insurance plan, and let y be the average administrative cost as a percentage of claims. Suppose a random sample of employees gave the following information. Given the scatter diagram and "best fit" line for the data below, would you say the correlation is low, moderate, or strong? Positive or negative? A) moderate and negative B) strong and negative C) moderate and positive D) low and negative E) low and positive Statistics - Ms. Metheny Page 4 Fall Semester Final Exam 2012 Review #2 ___ 11. The heights of 18-year-old men are approximately normally distributed with mean 68 inches and standard deviation 3 inches. What is the probability that an 18-year-old man selected at random is less than 72 inches tall? A) 0.0918 B) 0.9082 C) 0.4082 D) 0.8164 E) 0.1836 ___ 12. Suppose that about 27% of those called will find an excuse (work, poor health, travel out of town, etc.) to avoid jury duty. If 12 people are called for jury duty, what is the probability that 6 or more will not be available to serve on the jury? Round your answer to three decimal places. A) 0.978 B) 0.022 C) 0.076 D) 0.924 E) 0.097 ___ 13. Does the diagram below show a high linear correlation, a moderate or low linear correlation, or no linear correlation? A) high linear correlation B) no linear correlation Statistics - Ms. Metheny C) moderate or low linear correlation Page 5 Fall Semester Final Exam 2012 Review #2 ___ 14. Can a low barometer reading be used to predict maximum wind speed of an approaching tropical cyclone? Let x be the lowest pressure (in millibars) as a cyclone approaches, and let y be the maximum wind speed (in miles per hour) of the cyclone. Suppose a random sample of cyclones gave the following information. x 1014 935 980 955 995 y 50 80 60 135 84 Draw the line that best fits the data whose scatter diagram is given below. A) B) Statistics - Ms. Metheny Page 6 Fall Semester Final Exam 2012 Review #2 C) D) E) Statistics - Ms. Metheny Page 7 Fall Semester Final Exam 2012 Review #2 ___ 15. Finish times (to the nearest hour) for 59 dogsled teams are shown below. Draw a histogram. Use five classes. 278 296 284 296 288 288 247 256 261 270 236 244 338 360 341 333 261 266 287 296 313 311 306 306 299 303 277 283 304 305 288 290 288 289 297 299 332 330 309 326 306 326 285 291 295 298 306 315 310 318 318 320 333 321 323 324 327 302 319 A) B) Statistics - Ms. Metheny Page 8 Fall Semester Final Exam 2012 Review #2 C) D) E) Statistics - Ms. Metheny Page 9 Fall Semester Final Exam 2012 Review #2 ___ 16. Let z be a random variable with a standard normal distribution. Find the indicated probability below. P ( z ≥ 0.7 ) A) 0.242 B) 0.758 C) 0.621 D) 0.129 E) 0.258 ___ 17. True or false. The probability of some event is 1.25. A) false B) true ___ 18. Let x = red blood cell (RBC) count in millions per cubic millimeter of whole blood. Suppose for healthy females, x has an approximately normal distribution with mean μ = 4.9 and standard deviation σ = 0.2. Convert the following x interval from a laboratory test to a z interval. A) 4 < z B) –3 < z C) 4 > z 5.7 > x D) –2 > z E) –2 < z ___ 19. Look at the normal curve given below, and find σ . A) σ = 25 B) σ = 37 C) σ = 33 D) σ = 3 Statistics - Ms. Metheny E) σ = 4 Page 10 Fall Semester Final Exam 2012 Review #2 ___ 20. At Center Hospital there is some concern about the high turnover of nurses. A survey was done to determine how long (in months) nurses had been in their current positions. The responses (in months) of 20 nurses were 27 3 4 13 29 39 31 45 12 9 6 27 33 30 32 10 21 35 9 39 A box-and-whisker plot of the data is shown below. Find the interquartile range. A) 40.5 B) 25.0 C) 23.0 D) 42.0 E) 24.5 Statistics - Ms. Metheny Page 11 Fall Semester Final Exam 2012 Review #2 ___ 21. Finish times (to the nearest hour) for 10 dogsled teams are shown below. Make a frequency table showing class limits, class boundaries, midpoints, frequency, relative frequencies, and cumulative frequencies. Use three classes. (Round your answer for relative frequency to the nearest hundredth and for midpoint to the nearest tenth.) 262 236 272 256 294 242 288 258 284 310 Midpoint Freq. Relative Cumulative A) Class Limits Boundaries Freq. Freq. 236 − 260 235.5 − 260.5 248 4 0.4 4 261 − 284 260.5 − 284.5 273 3 0.3 7 285 − 308 284.5 − 308.5 297 3 0.3 10 B) Class Limits Boundaries Midpoint Freq. 236 − 260 261 − 285 286 − 310 248 273 298 4 3 3 Midpoint Freq. 248 273 297 5 5 4 Midpoint Freq. 248 273 297 5 5 4 235.5 − 260.5 260.5 − 285.5 285.5 − 310.5 C) Class Limits Boundaries 236 − 260 261 − 284 285 − 310 235.5 − 260.5 260.5 − 285.5 285.5 − 310.5 D) Class Limits Boundaries 236 − 260 261 − 284 285 − 308 235.5 − 260.5 260.5 − 284.5 284.5 − 308.5 Relative Freq. 0.4 0.3 0.3 Cumulative Freq. 4 7 10 Relative Freq. 0.4 0.3 0.3 Cumulative Freq. 4 7 10 Relative Freq. 0.4 0.3 0.3 Cumulative Freq. 4 7 10 E) none of theses choices ___ 22. How hot does it get in Death Valley? Assume that the following data are taken from a study conducted by the National Park System, of which Death Valley is a unit. The ground temperatures ( D F ) were taken from May to November in the vicinity of Furnace Creek. Compute the mean for these ground temperatures. Round your answer to the nearest tenth. 149 151 167 172 182 176 177 182 176 176 167 0 151 144 A) 142.6 B) 144.4 C) 155.2 D) 131.8 E) 142.2 ___ 23. Assuming that the heights of college women are normally distributed with mean 60 inches and standard deviation 2 inches, what percentage of women are shorter than 58 inches? A) 15.9% B) 50.0% C) 99.9% D) 84.1% E) 2.3% Statistics - Ms. Metheny Page 12 Fall Semester Final Exam 2012 Review #2 ___ 24. Are customers more loyal in the East or in the West? The following table is based on information from Trends in the United Sates, published by the food marketing Institute, Washington, D.C. The columns represent loyalty (in years) at a primary supermarket. The rows represent regions of the United Sates. Less 1 − 2 3 − 4 5 − 9 10 − 14 15 or More Row Than 1 Years Years Years Years Years Total Year East 32 54 59 112 77 118 452 Midwest 31 68 68 120 63 173 523 South 53 92 93 158 106 158 660 West 41 56 67 78 45 86 373 Column 157 270 287 468 291 535 2008 Total What is the probability that a customer chosen at random is from the West given that he or she has been loyal 10 to 14 years? Round your answer to the nearest thousand. A) 0.022 B) 0.155 C) 0.417 D) 0.121 E) none of these choices ___ 25. Suppose automobile insurance companies gave annual premiums for top-rated companies in several states. The figure below shows box plots for the annual premium for urban customers in three states. Which state has the highest median premium? A) Pennsylvania has the highest median premium. B) Texas has the highest median premium. C) Texas as well as California have the highest median premium. D) California has the highest median premium. E) none of these choices ___ 26. True or false. The law of large numbers states that in the long run, as the sample size or number of trials decreases, the relative frequency of outcomes gets closer to the theoretical probability of the outcome. A) false B) true Statistics - Ms. Metheny Page 13 Fall Semester Final Exam 2012 Review #2 ___ 27. The Grand Canyon and the Colorado River are beautiful, Rugged, and sometimes dangerous. Assume there is a physician at the park clinic in Grand Canyon Village. Suppose the physician has recorded (for a 5-year period) the number of visitor injuries at different landing points for commercial boat trips down the Colorado River in both the Upper and Lower Grand Canyon. Upper Canyon: Number of injuries per Landing Point Between North Canyon and Phantom Ranch 2 3 1 1 3 4 8 11 3 1 3 Lower Canyon: Number of injuries per Landing Point Between Bright Angel and Lava Falls 10 1 1 0 8 9 2 15 3 0 1 14 2 1 The mean, median, and mode for Upper Canyon are 3.636, 3.0, and 3, respectively. The mean, median, and mode for Lower Canyon are 4.857, 2.0, and 1, respectively. Compare the mean, median, and mode found in Upper Canyon and Lower Canyon, respectively. A) Lower Canyon mean is smaller than Upper Canyon, Lower Canyon median is smaller than Upper Canyon, and Lower Canyon mode is smaller than Upper Canyon. B) Lower Canyon mean is greater than Upper Canyon, Lower Canyon median is greater than Upper Canyon, and Lower Canyon mode is smaller than Upper Canyon. C) Lower Canyon mean is greater than Upper Canyon, Lower Canyon median is smaller than Upper Canyon, and Lower Canyon mode is greater than Upper Canyon. D) Lower Canyon mean is greater than Upper Canyon, Lower Canyon median is smaller than Upper Canyon, and Lower Canyon mode is smaller than Upper Canyon. E) Lower Canyon mean is greater than Upper Canyon, Lower Canyon median is greater than Upper Canyon, and Lower Canyon mode is greater than Upper Canyon. ___ 28. Give an example of a discrete random variable. A) The number of inches of rainfall in a county B) The number of beverages sold at a lemonade stand C) The number of gallons of concrete used at a construction site D) The time required for a runner to finish a marathon E) The temperature of a pot roast cooking in an oven ___ 29. Consider a binomial distribution with 15 trials. What is the expected value of this distribution if the probability of success on a single trial is 0.6? A) 24 B) 4 C) 25 D) 9 E) 8 Statistics - Ms. Metheny Page 14 Fall Semester Final Exam 2012 Review #2 ___ 30. Assume that the U.S Open Golf Tournament was played at Congressional Country club, with prizes ranging from $ 465,000 for first place to $ 5000. Par for the course is 70. The tournament consists of four rounds played on different days. Suppose the scores for each round of the 32 players who placed in the money (more than $ 17,000) were given on a web site. The scores for the first round were as follows: 71 63 68 73 74 73 71 71 74 73 74 71 75 71 72 71 78 75 71 71 74 75 67 66 76 75 76 71 72 72 73 71 The scores for the fourth round for these players were as follows: 69 69 72 74 72 72 71 71 71 70 72 73 73 72 71 71 71 69 70 71 71 73 74 72 71 68 69 70 69 71 73 74 The stem − and − leaf display of the fourth round is given below. 6 3 = score of 63 6 3 6 7 8 7 1 1 1 1 1 1 1 1 1 1 1 2 2 3 3 3 3 4 4 4 4 7 5 5 5 5 6 6 8 The stem − and − leaf display of the first round is given below. 6 8 = score of 68 6 8 9 9 9 9 9 7 0 0 0 0 1 1 1 1 1 1 1 1 2 2 2 2 2 2 3 3 3 3 3 4 4 4 Compare the two distributions. A) Scores are lower in the fourth round. C) Scores are equal for both the rounds. B) Scores are lower in the first round. D) none of these choices ___ 31. The qualified applicant pool for three management trainee positions consists of seven men and seven women. If the applicants are equally qualified and the trainee positions are selected by drawing the names at random so that all group of three are equally likely, what is the probability that the trainee class will consist entirely of women? Round your answer to the nearest thousandth. A) 0.005 B) 0.058 C) 0.096 D) 0.003 E) none of these choices ___ 32. When do creative people get their good ideas? Assume that the survey of 964 inventors gives the following information: Time of Day When Good Ideas Occur Time Number of Inventors 6 A.M. − 12 noon 280 12 noon − 6 P.M. 140 6 P.M. − 12 midnight 324 220 12 midnight − 6 A.M. Assuming that the time interval includes the left limit and all the times up to but not including the right limit, estimate the probability that an inventor has a good idea during both the time intervals from 12 noon to 6 P.M. and from 6 P.M. to midnight. Write your answer as a fraction in simplest form. 1 1 116 2835 A) B) C) D) E) none of these choices 2 4 241 58081 Statistics - Ms. Metheny Page 15 Fall Semester Final Exam 2012 Review #2 ___ 33. Use the list of random numbers given below to simulate the outcomes of tossing a quarter 11 times. Assume that the quarter is balanced (i.e., fair) and an even digit is assigned to the outcome heads (H) and an odd digit to the outcome tails (T). 91972398004 A) T T T T H T H H H H H D) T T T T H T T H H H T B) T T T T H T T H H H H E) T T T T H T T H H T H C) T T T T H H T H H H H ___ 34. Richard has been given a 5-question multiple-choice quiz in his history class. Each question has three answers, of which only one is correct. Since Richard has not attended the class recently, he doesn't know any of the answers. What is considered the failure? A) number of questions B) Richard answers a question correctly. C) number of questions Richard is unable to answer D) Richard is unable to answer a question correctly. E) none of the choices ___ 35. In your biology class, your final grade is based on several things: a lab score, score on two major tests, and your score on the final exam. There are 100 points available for each score. However, the lab score is worth 25% of your total grade, each major test is worth 22.5%, and the final exam is worth 30%. Compute the weighted average for the following scores: 90 on the lab, 82 on the first major test, 92 on the second major test, and 83 on the final exam. Round your answer to the nearest hundredth. A) 88.65 B) 84.80 C) 86.90 D) 86.55 E) 84.30 ___ 36. Consider the students in your statistics class as the population and suppose they are seated in five rows of 7 students each. To select a sample, you toss a coin. If it comes up heads, you use the 21 students sitting in the first three rows as your sample. If it comes up tails, you use 21 students sitting in last three rows as your sample. True or false: Every student has an equal chance of being selected for the sample. A) false B) true ___ 37. Plain candies come in various colors. Assume that the distribution of colors for plain candies is as follows: Color Purpl Yello Red Orang Green Blue Brown e w e Percent 17% 20% 19% 9% 9% 7% 19% Suppose you have a large bag of plain candies and you take one candy at random. Find the probability that the candy is either brown or green, if the probability that you take brown candy is 0.19 and the probability that you take green candy is 0.09. Round your answer to the nearest hundredth. A) 0.02 B) 0.28 C) 0.39 D) 0.29 E) none of these choices ___ 38. Consider the data that was obtained from a random sample of 41 credit card accounts. Identify all the averages (mean, median, or mode) that can be used to summarize the name of credit card (e.g., MasterCard, Visa, American Express, etc.) A) mode if it exists D) mean, median, and mode if it exists B) median if it exists E) mean and mode if it exists C) mean if it exists Statistics - Ms. Metheny Page 16 Fall Semester Final Exam 2012 Review #2 ___ 39. If the probability that an event will happen is 0.27, what is the probability that the event won’t happen? A) 0.23 B) 0.63 C) 0.73 D) 0.83 E) 1.73 ___ 40. Assume that x has a normal distribution, with the specified mean and standard deviation. Find the indicated probabilities. P ( x ≥ 28) ; μ = 27; σ = 5 A) 0.421 B) 0.290 C) 0.579 D) 0.210 E) 0.079 Statistics - Ms. Metheny Page 17 Fall Semester Final Exam 2012 Review #2 Answer Key 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. 34. 35. 36. 37. 38. 39. 40. D B D D A E D C E B B C C E C A A C E C B C A B B A D B D B C D B D D A B A C A Statistics - Ms. Metheny Page 18