Math 2201 – Review Unit 5 Multiple Choice Identify the choice that best completes the statement or answers the question. ____ 1. Determine the range of the following test scores. History Test 1 Scores (out of 100) 90 84 77 66 89 84 77 65 86 82 75 65 86 81 72 61 84 79 70 56 a. b. c. d. ____ 2. Determine the mean of the following test scores. History Test 1 Scores (out of 100) 90 84 77 66 89 84 77 65 86 82 75 65 86 81 72 61 84 79 70 56 a. b. c. d. ____ 79.2 78.5 74.25 76.45 3. Determine the median of the following test scores. History Test 1 Scores (out of 100) 90 84 77 66 89 84 77 65 86 82 75 65 86 81 72 61 84 79 70 56 a. b. c. d. ____ 34 56 90 78 78 79 56 77 4. Environment Canada compiled data on the number of lightning strikes per square kilometre in Alberta and British Columbia towns from 1999 to 2008. 0.42 0.04 0.81 0.40 0.03 0.74 0.28 0.03 0.70 0.23 0.03 0.66 0.13 0.02 0.61 0.12 0.01 0.58 0.10 0.00 0.49 0.07 1.08 0.43 0.05 0.91 0.42 0.04 0.88 What value goes in the fourth row of this frequency table? Lightning Strikes (per square kilometre) Frequency 0.00–0.19 13 0.20–0.39 2 0.40–0.59 6 0.60–0.79 0.80–0.99 3 1.00–1.19 1 a. b. c. d. ____ 5. The range of a set of data is 7.5 and the minimum value is 2.8. To display this data in a histogram, Yul chose intervals of 1.5 starting with 2.5–3.9. How many intervals will his histogram have? a. b. c. d. ____ 5 4 6 3 7 4 6 5 6. Environment Canada compiled data on the number of lightning strikes per square kilometre in Alberta and British Columbia towns from 1999 to 2008. 0.42 0.04 0.81 0.40 0.03 0.74 0.28 0.03 0.70 0.23 0.03 0.66 0.13 0.02 0.61 0.12 0.01 0.58 0.10 0.00 0.49 0.07 1.08 0.43 0.05 0.91 0.42 0.04 0.88 Which range of data occurs least frequently? a. b. c. d. ____ 0.60–0.69 0.70–0.79 0.50–0.59 0.40–0.49 7. At the end of a bowling tournament, three friends analyzed their scores. Erinn’s mean bowling score is 92 with a standard deviation of 14. Declan’s mean bowling score is 130 with a standard deviation of 18. Matt’s mean bowling score is 116 with a standard deviation of 22. Who had the highest scoring game during the tournament? a. Declan b. Matt c. Impossible to tell. d. Erinn ____ 8. A pear orchard has 20 trees with these heights, given in inches. 110 83 104 95 88 80 115 106 97 100 98 93 92 117 75 83 122 115 89 105 Determine the standard deviation, to one decimal place. a. b. c. d. ____ 15.0 in. 11.0 in. 9.0 in. 13.0 in. 9. Chinedu recorded the time it takes him to get to school using three different routes. Hour Route 1 (min) Route 2 (min) Route 3 (min) 1 13 20 16 2 15 18 17 3 12 20 15 4 12 12 17 5 16 17 22 On which route does Chinedu have a more consistent travel time? a. Route 3 b. Route 1 c. Route 2 ____ 10. A set of data is normally distributed. What percent of the data is within one standard deviation of the mean? a. b. c. d. about 95% about 68% 100% about 50% ____ 11. Which description does not describe the normal curve? a. b. c. d. starts off increasing symmetrical shaped like a bell always increasing ____ 12. The ages of participants in a bonspiel are normally distributed, with a mean of 40 and a standard deviation of 10 years. What percent of the curlers are between 40 and 50? a. b. c. d. 68% 95% 16% 34% ____ 13. Which set is normally distributed? 0–9 10–19 Interval 20–29 30–39 40–49 50–59 Set A. Set B. Set C. Set D. a. b. c. d. 100 800 950 400 500 750 420 620 850 700 180 760 820 650 220 820 450 600 460 900 150 550 990 850 Set C. Set B. Set D. Set A. ____ 14. Determine the z-score for the given value. µ = 52, = 6, x = 64 a. b. c. d. 0.5 2 –0.5 –2 ____ 15. Determine the percent of data between the following z-scores: z = –1.50 and z = 1.50. a. b. c. d. 100% 88.82% 94.41% 47.20% ____ 16. A poll was conducted about an upcoming election. The results are considered accurate within ±2.7 percent points, 19 times out of 20. State the confidence level. a. b. c. d. 99% 19% 90% 95% ____ 17. A poll was conducted about an upcoming election. The result that 54% of people intend to vote for one of the candidates is considered accurate within ±7.1 percent points, 19 times out of 20. State the confidence interval. a. b. c. d. 54%–61.1% 47.1%–60.9% 46.9%–61.1% 46.9%–54% ____ 18. The results of a survey have a confidence interval of 56.0% to 64.6%, 9 times out of 10. Determine the margin of error. a. b. c. d. ±64.6% ±16.6% ±8.3% ±56.0% ____ 19. In a recent survey of high school students, 72% of those surveyed agreed that school should start half an hour later. The survey is considered accurate to within 3.5 percent points, 19 times out of 20. If a high school has 1200 students, state the range of the number of students who would agree with the survey. a. b. c. d. 822–864 864–906 822–906 864–948 ____ 20. A teacher is analyzing the class results for a physics test. The marks are normally distributed with a mean (µ) of 76 and a standard deviation () of 4. Determine Guy’s mark if he scored µ + 2. a. b. c. d. 80 68 72 84 Short Answer 21. A teacher is analyzing the class results for a computer science test. The marks are normally distributed with a mean (µ) of 79.5 and a standard deviation () of 3.5. Determine Daryl’s mark if he scored µ + . 22. The results of a survey have a confidence interval of 77.2% to 91.6%, 99 times out of 100. Determine the margin of error. 23. Khamid and Gerbrand are laying interlocking bricks. Their supervisor records how many bricks they lay each hour. 1 2 3 4 5 6 Hour 212 193 204 195 182 216 Khamid 230 195 214 207 218 191 Gerbrand Which worker is more consistent? Problem 24. Four groups of students recorded their pulse rates after a 2 km run. Group 1 126 168 158 192 146 166 104 164 Group 2 158 132 156 160 108 150 178 136 Group 3 136 174 156 176 150 166 142 156 Group 4 144 150 142 152 174 176 118 152 116 172 130 178 a) Make a frequency table with five intervals to organize the pulse rates. b) Construct a histogram of the data. 138 140 182 164 25. A tile company produces glass kitchen tiles that has an average thickness of 71 mm, with a standard deviation of 0.4 mm. For premium-quality tiles, the tiles must have a thickness between 70 mm and 71.5 mm. What percent, to the nearest whole number, of the total production can be sold as premium-quality tiles? 26. In a pre-election survey in Vancouver, 16.5% of those surveyed said they were undecided about whom to vote for in the mayoral election. The survey is considered accurate to within 5.2 percent points, 19 times out of 20. a) Determine the confidence level and the confidence interval. b) If there are 425 000 eligible voters in Vancouver, state the range of the number of people who are undecided. 27. Leon keeps track of the amount he spends, in dollars, on weekly lunches during one semester: 25 19 36 19 17 10 24 33 24 28 25 31 28 26 29 26 18 32 a) Determine the range, mean, and standard deviation, correct to two decimal places. b) Remove the greatest and the least weekly amounts. Then determine the range, mean, and standard deviation for the remaining amounts. c) What effect does removing the greatest and the least amounts have on the three values? 28. Jackson raises Siberian husky sled dogs at his kennel. He knows, from the data he has collected over the years, that the masses of adult male dogs are normally distributed, with a mean of 23.6 kg and a standard deviation of 1.8 kg. How many of his 87 adult male dogs would you expect to be in the range 21.8 kg to 25.4 kg? 29. In a population, 80% of the adults are taller than 165 cm and 20% are taller than 187 cm. Determine the mean height and standard deviation for this population. Math 2201 - ICA ch. 5 Answer Section MULTIPLE CHOICE 1. ANS: A PTS: 1 DIF: Grade 11 REF: Lesson 5.1 TOP: Exploring data KEY: range 2. ANS: C PTS: 1 DIF: Grade 11 REF: Lesson 5.1 TOP: Exploring data KEY: mean 3. ANS: A PTS: 1 DIF: Grade 11 REF: Lesson 5.1 TOP: Exploring data KEY: median 4. ANS: B PTS: 1 DIF: Grade 11 REF: Lesson 5.2 TOP: Frequency tables, histograms, and frequency polygons KEY: frequency distribution | histogram | frequency polygon 5. ANS: C PTS: 1 DIF: Grade 11 REF: Lesson 5.2 TOP: Frequency tables, histograms, and frequency polygons KEY: frequency distribution | histogram 6. ANS: C PTS: 1 DIF: Grade 11 REF: Lesson 5.2 TOP: Frequency tables, histograms, and frequency polygons KEY: frequency distribution 7. ANS: C PTS: 1 DIF: Grade 11 REF: Lesson 5.3 OBJ: 1.3 Explain, using examples, the properties of a normal curve, including the mean, median, mode, standard deviation, symmetry and area under the curve. TOP: Standard deviation KEY: mean | standard deviation 8. ANS: D PTS: 1 DIF: Grade 11 REF: Lesson 5.3 OBJ: 1.2 Calculate, using technology, the population standard deviation of a data set. | 1.3 Explain, using examples, the properties of a normal curve, including the mean, median, mode, standard deviation, symmetry and area under the curve. TOP: Standard deviation KEY: standard deviation 9. ANS: C PTS: 1 DIF: Grade 11 REF: Lesson 5.3 OBJ: 1.2 Calculate, using technology, the population standard deviation of a data set. | 1.3 Explain, using examples, the properties of a normal curve, including the mean, median, mode, standard deviation, symmetry and area under the curve. TOP: Standard deviation KEY: standard deviation 10. ANS: B PTS: 1 DIF: Grade 11 REF: Lesson 5.4 OBJ: 1.3 Explain, using examples, the properties of a normal curve, including the mean, median, mode, standard deviation, symmetry and area under the curve. TOP: The normal distribution KEY: normal distribution | mean | standard deviation 11. ANS: D PTS: 1 DIF: Grade 11 REF: Lesson 5.4 OBJ: 1.3 Explain, using examples, the properties of a normal curve, including the mean, median, mode, standard deviation, symmetry and area under the curve. TOP: The normal distribution KEY: normal curve 12. ANS: D PTS: 1 DIF: Grade 11 REF: Lesson 5.4 OBJ: 1.7 Solve a contextual problem that involves the interpretation of standard deviation. | 1.9 Solve a contextual problem that involves normal distribution. TOP: The normal distribution KEY: normal distribution | mean | standard deviation 13. ANS: D PTS: 1 DIF: Grade 11 REF: Lesson 5.4 OBJ: 1.4 Determine if a data set approximates a normal distribution, and explain the reasoning. TOP: The normal distribution KEY: normal distribution 14. ANS: B PTS: 1 DIF: Grade 11 REF: Lesson 5.5 15. 16. 17. 18. 19. 20. OBJ: 1.8 Determine, with or without technology, and explain the z-score for a given value in a normally distributed data set. TOP: Applying the normal distribution: z-scores KEY: z-score | standard normal distribution ANS: B PTS: 1 DIF: Grade 11 REF: Lesson 5.5 OBJ: 1.8 Determine, with or without technology, and explain the z-score for a given value in a normally distributed data set. TOP: Applying the normal distribution: z-scores KEY: z-score | standard normal distribution ANS: D PTS: 1 DIF: Grade 11 REF: Lesson 5.6 OBJ: 2.1 Explain, using examples, how confidence levels, margin of error and confidence intervals may vary depending on the size of the random sample. | 2.2 Explain, using examples, the significance of a confidence interval, margin of error or confidence level. TOP: Confidence intervals KEY: margin of error | confidence interval | confidence level ANS: C PTS: 1 DIF: Grade 11 REF: Lesson 5.6 OBJ: 2.1 Explain, using examples, how confidence levels, margin of error and confidence intervals may vary depending on the size of the random sample. | 2.2 Explain, using examples, the significance of a confidence interval, margin of error or confidence level. TOP: Confidence intervals KEY: margin of error | confidence interval | confidence level ANS: C PTS: 1 DIF: Grade 11 REF: Lesson 5.6 OBJ: 2.1 Explain, using examples, how confidence levels, margin of error and confidence intervals may vary depending on the size of the random sample. | 2.2 Explain, using examples, the significance of a confidence interval, margin of error or confidence level. TOP: Confidence intervals KEY: margin of error | confidence interval | confidence level ANS: C PTS: 1 DIF: Grade 11 REF: Lesson 5.6 OBJ: 2.1 Explain, using examples, how confidence levels, margin of error and confidence intervals may vary depending on the size of the random sample. | 2.2 Explain, using examples, the significance of a confidence interval, margin of error or confidence level. TOP: Confidence intervals KEY: margin of error | confidence interval | confidence level ANS: D PTS: 1 DIF: Grade 11 REF: Lesson 5.4 OBJ: 1.7 Solve a contextual problem that involves the interpretation of standard deviation. | 1.9 Solve a contextual problem that involves normal distribution. TOP: The normal distribution KEY: normal distribution | mean | standard deviation SHORT ANSWER 21. ANS: 83.0 PTS: 1 DIF: Grade 11 REF: Lesson 5.4 OBJ: 1.7 Solve a contextual problem that involves the interpretation of standard deviation. | 1.9 Solve a contextual problem that involves normal distribution. TOP: The normal distribution KEY: normal distribution | mean | standard deviation 22. ANS: ±7.2% PTS: 1 DIF: Grade 11 REF: Lesson 5.6 OBJ: 2.1 Explain, using examples, how confidence levels, margin of error and confidence intervals may vary depending on the size of the random sample. | 2.2 Explain, using examples, the significance of a confidence interval, margin of error or confidence level. TOP: Confidence intervals KEY: margin of error | confidence level | confidence interval 23. ANS: Khamid has the lower standard deviation. PTS: 1 DIF: Grade 11 REF: Lesson 5.3 OBJ: 1.2 Calculate, using technology, the population standard deviation of a data set. | 1.3 Explain, using examples, the properties of a normal curve, including the mean, median, mode, standard deviation, symmetry and area under the curve. TOP: Standard deviation KEY: standard deviation PROBLEM 24. ANS: a) Interval 100–119 120–139 140–159 160–179 180–199 Frequency 4 6 15 13 2 b) PTS: 1 DIF: Grade 11 REF: Lesson 5.2 TOP: Frequency tables, histograms, and frequency polygons 25. ANS: Determine the two z-scores: KEY: frequency distribution | histogram The z-scores are –2.5 and 1.25. Using the z-score table, 89.44% – 1.62% = 87.82% of the data is between these two z-scores. About 88% of the total production can be sold as premium-quality tiles. PTS: 1 DIF: Grade 11 REF: Lesson 5.5 OBJ: 1.7 Solve a contextual problem that involves the interpretation of standard deviation. | 1.8 Determine, with or without technology, and explain the z-score for a given value in a normally distributed data set. | 1.9 Solve a contextual problem that involves normal distribution. TOP: Applying the normal distribution: z-scores KEY: normal distribution | mean | standard deviation | z-score 26. ANS: a) The confidence level is 19 times out of 20 or 95%. 16.5% – 5.2% = 11.3% 16.5% + 5.2% = 21.7% The confidence interval is 11.3% to 21.7%. b) 0.113(425 000) = 48 025 0.217(425 000) = 92 225 The number of people who are undecided should be in the range of 48 025 to 92 225. PTS: 1 DIF: Grade 11 REF: Lesson 5.6 OBJ: 1.6 Explain, using examples that represent multiple perspectives, the application of standard deviation for making decisions in situations such as warranties, insurance or opinion polls. | 1.9 Solve a contextual problem that involves normal distribution. | 2.3 Make inferences about a population from sample data, using given confidence intervals, and explain the reasoning. TOP: Confidence intervals KEY: mean | range | standard deviation | margin of error | confidence level | confidence interval 27. ANS: a) The maximum value is 33 and the minimum value is 10 so the range is 23. Using technology, the mean is 25 and the standard deviation is about 6.3. b) The maximum value is now 32 and the minimum value is now 17 so the range is 15. Using technology, the mean is about 25.4 and the standard deviation is about 5.2. c) Removing the greatest and the least amounts decreases the range and the standard deviation. The mean stayed about the same. PTS: 1 DIF: Grade 11 REF: Lesson 5.3 OBJ: 1.2 Calculate, using technology, the population standard deviation of a data set. | 1.3 Explain, using examples, the properties of a normal curve, including the mean, median, mode, standard deviation, symmetry and area under the curve. | 1.5 Compare the properties of two or more normally distributed data sets. TOP: Standard deviation KEY: mean | median | range | standard deviation 28. ANS: 21.8 = 23.6 – 1(1.8) 25.4 = 23.6 + 1(1.8) Since 21.8 kg is one standard deviation below the mean and 25.4 kg is one standard deviation above the mean, I would expect 68% of the adult male dogs to be in this range. 0.68(87) = 59.16 I would expect 59 adult male dogs to be in the range of 21.8 kg to 25.4 kg. PTS: 1 DIF: Grade 11 REF: Lesson 5.4 OBJ: 1.3 Explain, using examples, the properties of a normal curve, including the mean, median, mode, standard deviation, symmetry and area under the curve. | 1.7 Solve a contextual problem that involves the interpretation of standard deviation. | 1.9 Solve a contextual problem that involves normal distribution. TOP: The normal distribution KEY: normal distribution | mean | standard deviation 29. ANS: If 20% of the population is to the left of 165 cm and 20% of the population is to the right of 187 cm, then the mean of these heights is the mean height of the population: The mean height is 176 cm. Then 20% of the population to the right of 187 cm is 80% or 0.80 of the population to the left of the 187 cm. Using the z-score table, 0.80 corresponds to a z-score of 0.84. The standard deviation is 13.1 cm. PTS: 1 DIF: Grade 11 REF: Lesson 5.5 OBJ: 1.7 Solve a contextual problem that involves the interpretation of standard deviation. | 1.8 Determine, with or without technology, and explain the z-score for a given value in a normally distributed data set. | 1.9 Solve a contextual problem that involves normal distribution. TOP: Applying the normal distribution: z-scores KEY: normal distribution | mean | standard deviation | z-score