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Mode: Since 1.5, 2, and 2.5 appear twice, the modes are 1.5, 2, and 2.5 inches of rain. Chapter Review Find the mean, median, and mode for each set of data. Round to the nearest tenth, if necessary. 1. number of students in each math class: 22, 23, 24, 22, 21 SOLUTION: Mean: The mean is 22.4 students. Median: Order the numbers from least to greatest. 21, 22, 22, 23, 24 The median number of students in the math classes is 22. Mode: There are two classes with 22 students, so the mode is 22 students. ANSWER: 22.4 students; 22 students; 22 students 3. inches of rain last week: 1.5, 2, 2.5, 2, 1.5, 2.5, 3 SOLUTION: Mean: The mean is approximately 2.1 inches. Median: Order the numbers from least to greatest. 1.5, 1.5, 2, 2, 2.5, 2.5, 3 The median number of inches of rain is 2. Mode: Since 1.5, 2, and 2.5 appear twice, the modes are 1.5, 2, and 2.5 inches of rain. ANSWER: 2.1 in.; 2 in.; 1.5 in., 2 in., 2.5 in. 4. At the movie theater, six movies are playing and their lengths are 138, 117, 158, 145, 135, and 120 minutes. Which measure of center best represents the data? Justify your selection and then find the measure of center. SOLUTION: Because there are no extreme values or numbers that are identical, the mean would best represent the data. eSolutions Manual - Powered by Cognero Mean: ANSWER: 2.1 in.; 2 in.; 1.5 in., 2 in., 2.5 in. 4. At the movie theater, six movies are playing and their lengths are 138, 117, 158, 145, 135, and 120 minutes. Which measure of center best represents the data? Justify your selection and then find the measure of center. SOLUTION: Because there are no extreme values or numbers that are identical, the mean would best represent the data. Mean: The mean is 135.5 minutes. ANSWER: Mean; there are no extreme values or numbers that are identical; 135.5 min Find the measures of variability and any outliers for each set of data. 6. The number of fish in each fish tank: 6, 5, 7, 8, 5, 6, 7, 9, 8, 6 SOLUTION: Range: The greatest value is 9 and the least value is 5. So, the range is 9 – 5 or 4 fish. Median, First Quartile, and Third Quartile: List the data from the least to greatest. 5, 5, 6, 6, 6, 7, 7, 8, 8, 9 There is an even number of items, so find the mean of the middle two numbers. The median number of fish is 6.5. The first quartile, or median of the lower half, is 6. The third quartile, or median of the upper half, is 8. The interquartile range is 8 – 6 or 2. Outliers: To determine if there are any outliers, multiply the interquartile range, 2, by 1.5. 2 • 1.5 = 3 Subtract 3 from the first quartile and add 3 to the third quartile. 6 – 3 = 3; 8 + 3 = 11 There are no values less than 3 or greater than 11, so there are no outliers. ANSWER: R: 4; M: 6.5; Q1: 6; Q3: 8; IR 2; none Page 1 7. Claire earned $5, $7, $10, $6, and $8 doing errands for her neighbors. Find the measures of variability and any outliers for the set of data. The mean is 135.5 minutes. there are no outliers. ANSWER: Mean; there are no extreme values or numbers that are identical; 135.5 min ANSWER: R: 4; M: 6.5; Q1: 6; Q3: 8; IR 2; none Chapter Review Find the measures of variability and any outliers for each set of data. 6. The number of fish in each fish tank: 6, 5, 7, 8, 5, 6, 7, 9, 8, 6 SOLUTION: Range: The greatest value is 9 and the least value is 5. So, the range is 9 – 5 or 4 fish. Median, First Quartile, and Third Quartile: List the data from the least to greatest. 5, 5, 6, 6, 6, 7, 7, 8, 8, 9 There is an even number of items, so find the mean of the middle two numbers. 7. Claire earned $5, $7, $10, $6, and $8 doing errands for her neighbors. Find the measures of variability and any outliers for the set of data. SOLUTION: Range: The greatest value is 10 and the least value is 5. So, the range is 10 – 5 or $5. Median, First Quartile, and Third Quartile: List the data from the least to greatest. 5, 6, 7, 8, 10 The median amount Claire spent is $7. The first quartile, or median of the lower half, is or 5.5. The third quartile, or median of the upper half, is The median number of fish is 6.5. The first quartile, or median of the lower half, is 6. The third quartile, or median of the upper half, is 8. The interquartile range is 8 – 6 or 2. Outliers: To determine if there are any outliers, multiply the interquartile range, 2, by 1.5. 2 • 1.5 = 3 Subtract 3 from the first quartile and add 3 to the third quartile. 6 – 3 = 3; 8 + 3 = 11 There are no values less than 3 or greater than 11, so there are no outliers. ANSWER: R: 4; M: 6.5; Q1: 6; Q3: 8; IR 2; none 7. Claire earned $5, $7, $10, $6, and $8 doing errands for her neighbors. Find the measures of variability and any outliers for the set of data. SOLUTION: Range: The greatest value is 10 and the least value is 5. So, the range is 10 – 5 or $5. Median, First Quartile, and Third Quartile: List the data from the least to greatest. 5, 6, 7, 8, 10 The median amount Claire spent is $7. The first quartile, or median of the lower half, is or 5.5. The third quartile, or median of the upper half, is or 9. The interquartile range is 9 – 5.5 or 3.5. Outliers: To determine if there are any outliers, multiply the interquartile range, 3.5, by 1.5. eSolutions Manual Powered by Cognero 3.5 • 1.5 = -5.25 Subtract 5.25 from the first quartile and add 5.25 to the third quartile. or 9. The interquartile range is 9 – 5.5 or 3.5. Outliers: To determine if there are any outliers, multiply the interquartile range, 3.5, by 1.5. 3.5 • 1.5 = 5.25 Subtract 5.25 from the first quartile and add 5.25 to the third quartile. 5.5 – 5.25 = 0.25; 9 + 5.25 = 14.25 There are no values less than 0.25 or greater than 14.25, so there are no outliers. ANSWER: R: 5; M: 7; Q1: 5.5; Q3: 9; IR 3.5; none 8. The scores Mr. Han’s students earned on their last test are shown in the table. Use the measures of variability to describe the data in the table. SOLUTION: The greatest value is 99 and the least value is 58. So, the spread of the data, or range, is 41 points. The data ordered from the least to greatest is 58, 73, 74, 74, 74, 76, 76, 77, 80, 81, 82, 82, 82, 83, 84, 85, 86, 87, 88, 89, 92, 92, 99, and 99. There is an even number of items, so find the mean of the middle two numbers. Page 2 The median test score is 82 points. The lower quartile, or median of the lower half, is or There are no values less than 0.25 or greater than 14.25, so there are no outliers. ANSWER: R: 5; M: 7; Q1: 5.5; Q3: 9; IR 3.5; none Chapter Review 8. The scores Mr. Han’s students earned on their last test are shown in the table. Use the measures of variability to describe the data in the table. The spread of the data is 41 points. The median is 82 points. One fourth of the students earned 76 points or less. One fourth of the students earned 87.5 points or more. Half of the students earned between 76 and 87.5 points. Find the mean absolute deviation of each data set. 9. 25, 70, 75, 100 SOLUTION: Find the mean. Find the absolute differences between each data value and the mean. SOLUTION: The greatest value is 99 and the least value is 58. So, the spread of the data, or range, is 41 points. The data ordered from the least to greatest is 58, 73, 74, 74, 74, 76, 76, 77, 80, 81, 82, 82, 82, 83, 84, 85, 86, 87, 88, 89, 92, 92, 99, and 99. There is an even number of items, so find the mean of the middle two numbers. Find the average of these differences. The average distance between each data value and the mean is 21.25. The median test score is 82 points. The lower quartile, or median of the lower half, is or 76. One fourth of the students earned 76 points or less. The upper quartile, or median of the upper half, is or 87.5. One fourth of the students earned 87.5 points or more. The interquartile range is 87.5 – 76 or 11.5. One half of the students earned between 76 and 87.5 points. ANSWER: The spread of the data is 41 points. The median is 82 points. One fourth of the students earned 76 points or less. One fourth of the students earned 87.5 points or more. Half of the students earned between 76 and 87.5 points. Find the mean absolute deviation of each data set. 9. 25, 70, 75, 100 SOLUTION: Find the mean. Find the absolute differences between each data value and the mean. eSolutions Manual - Powered by Cognero ANSWER: 21.25 11. 35, 50, 40, 55, 45 SOLUTION: Find the mean. Find the absolute differences between each data value and the mean. Find the average of these differences. The average distance between each data value and the mean is 6. ANSWER: 6 14. The table shows the numbers of two colors of Page 3 candies in several bags. Which data set has a greater mean absolute deviation? Justify your answer. The average distance between each data value and the mean is 6. ANSWER: Chapter Review 6 14. The table shows the numbers of two colors of candies in several bags. Which data set has a greater mean absolute deviation? Justify your answer. The set of brown candies has a greater mean absolute deviation. ANSWER: Brown candies; the mean absolute deviation is 2.32, which is greater than 1.92, the mean absolute deviation of the red candies. 15. The double box plot shows the numbers of floors for buildings on two streets. Compare the centers and variations. Write an inference you can draw about the two populations. SOLUTION: Find the mean of the brown candies. Find the absolute value of the differences between each data value and the mean. Find the average of these differences. The mean absolute deviation of the brown candies is 2.32. Find the mean of the red candies. Find the absolute value of the differences between each data value and the mean. Find the average of these differences. The mean absolute deviation of the red candies is 1.92. The set of brown candies has a greater mean absolute deviation. ANSWER: Brown candies; the mean absolute deviation is 2.32, which is greater than 1.92, the mean absolute deviation of the red candies. eSolutions Manual - Powered by Cognero 15. The double box plot shows the numbers of floors for buildings on two streets. Compare the centers and SOLUTION: The median number of floors on Main St. is 40 with an interquartile range of 10. The median number of floors on Grand Ave. is 18 with an interquartile range of 5. Main St. has more variability and centers around a higher number of floors than Grand Ave. ANSWER: The median number of floors on Main St. is 40 with an interquartile range of 10. The median number of floors on Grand Ave. is 18 with an interquartile range of 5. Main St. has more variability and centers around a higher number of floors than Grand Ave. 16. To determine the weekly top ten songs, the local radio station asks people to log onto their Web site and vote for their favorite song. Identify the sample as biased or unbiased and describe its type. Explain. SOLUTION: The sample is biased because it is a voluntary response survey. Only those people who are interested in participating in the survey are part of the sample. ANSWER: biased, voluntary response survey; only those people who are interested in participating in the survey are part of the sample. 17. Forty-five out of 60 people at a steakhouse said their favorite meal was steak. Is this sampling representative of the entire town? If so, how many of the 13,000 residents would say steak was their favorite meal? SOLUTION: This is a biased, convenience sample because only customers in one restaurant specializing in steak were surveyed. So, this sampling method is not representative of the entire town. Page 4 ANSWER: No; The sample is biased. Diners at a steakhouse are more likely to choose steak as their favorite meal. ANSWER: biased, voluntary response survey; only those people who are interested in participating in the survey are part of the sample. Chapter Review 17. Forty-five out of 60 people at a steakhouse said their favorite meal was steak. Is this sampling representative of the entire town? If so, how many of the 13,000 residents would say steak was their favorite meal? The probability is 0 or 0%. Because the probability of the event is 0%, the event is impossible. ANSWER: 0 or 0%; impossible 19. P(two-digit number) SOLUTION: sample space: {1, 4, 9, 16, 25, 36, 49, 64, 81, 100} favorable outcomes: 16, 25, 36, 49, 64, and 81 SOLUTION: This is a biased, convenience sample because only customers in one restaurant specializing in steak were surveyed. So, this sampling method is not representative of the entire town. The probability is ANSWER: No; The sample is biased. Diners at a steakhouse are more likely to choose steak as their favorite meal. Mike rolls a ten-sided solid whose identical faces are numbered with the first ten square numbers. Find each probability. Then describe the likelihood of the event as impossible, unlikely, equally likely, likely, or certain. 18. P(ones digit is 2) SOLUTION: sample space: {1, 4, 9, 16, 25, 36, 49, 64, 81, 100} favorable outcomes: none The probability is 0 or 0%. Because the probability of the event is 0%, the event is impossible. or 60%. Because the probability of the event is greater than 50%, the event is likely to occur. ANSWER: or 60%; likely 20. P(multiple of 8) SOLUTION: sample space: {1, 4, 9, 16, 25, 36, 49, 64, 81, 100} favorable outcomes: 16 and 64 The probability is or 20%. Because the probability of the event is less than 50%, the event is unlikely to occur. ANSWER: 0 or 0%; impossible ANSWER: 19. P(two-digit number) or 20%; unlikely SOLUTION: sample space: {1, 4, 9, 16, 25, 36, 49, 64, 81, 100} favorable outcomes: 16, 25, 36, 49, 64, and 81 21. P(ones digit not 3) SOLUTION: sample space: {1, 4, 9, 16, 25, 36, 49, 64, 81, 100} favorable outcomes: 1, 4, 9, 16, 25, 36, 49, 64, 81, and 100 The probability is or 60%. Because the probability of the event is greater than 50%, the event is likely to occur. ANSWER: eSolutions Manual - Powered by Cognero or 60%; likely The probability is 1 or 100%. Because the probability of the event is 100%, the event is certain. ANSWER: 1 or 100%; certain 22. P(odd) Page 5 occur. occur. ANSWER: ANSWER: or 20%; unlikely Chapter Review or 50%; equally likely 21. P(ones digit not 3) 23. P(one-digit number) SOLUTION: sample space: {1, 4, 9, 16, 25, 36, 49, 64, 81, 100} favorable outcomes: 1, 4, 9, 16, 25, 36, 49, 64, 81, and 100 SOLUTION: sample space: {1, 4, 9, 16, 25, 36, 49, 64, 81, 100} favorable outcomes: 1, 4, and 9 The probability is The probability is 1 or 100%. Because the probability of the event is 100%, the event is certain. ANSWER: 1 or 100%; certain or 30%. Because the probability of the event is less than 50%, the event is unlikely to occur. ANSWER: or 30%; unlikely 22. P(odd) SOLUTION: sample space: {1, 4, 9, 16, 25, 36, 49, 64, 81, 100} favorable outcomes: 1, 9, 25, 49, and 81 In a survey of randomly selected students, students chose their preference from among three meal options for a school event. 25. What was the experimental probability that a student chose burgers? SOLUTION: The probability is or 50%. Because the probability of the event is 50%, the event is equally likely to occur. ANSWER: ANSWER: or 50%; equally likely 23. P(one-digit number) SOLUTION: sample space: {1, 4, 9, 16, 25, 36, 49, 64, 81, 100} favorable outcomes: 1, 4, and 9 The probability is 26. What was the experimental probability that a student chose the vegetarian option? SOLUTION: or 30%. Because the probability of the event is less than 50%, the event is unlikely to occur. ANSWER: ANSWER: 30%;- Powered unlikelyby Cognero eSolutions or Manual In a survey of randomly selected students, Page 6 28. Out of a similar group of 450 students, predict how many would choose the vegetarian option. ANSWER: Chapter Review 26. What was the experimental probability that a student chose the vegetarian option? SOLUTION: Out of a similar group of 450 students, 99 would choose the vegetarian option. ANSWER: 99 A box contains 8 red markers, 5 green markers, and 5 blue markers. Once a marker is pulled from the box, it is replaced, and then another marker is pulled. Find each probability. 29. P(red, then green) SOLUTION: When drawing the first marker, there are 8 + 5 + 5 or 18 markers, and 8 of them are red. ANSWER: The first marker is replaced. When drawing the second marker, there are 18 markers, and 5 of them are green. 28. Out of a similar group of 450 students, predict how many would choose the vegetarian option. SOLUTION: Use the percent proportion to find 22% of 450. The probability of drawing a red marker then a green marker is Out of a similar group of 450 students, 99 would choose the vegetarian option. . ANSWER: ANSWER: 99 A box contains 8 red markers, 5 green markers, and 5 blue markers. Once a marker is pulled from the box, it is replaced, and then another marker is pulled. Find each probability. 29. P(red, then green) SOLUTION: When drawing the first marker, there are 8 + 5 + 5 or 18 markers, and 8 of them are red. The first marker is replaced. When drawing the second marker, there are 18 markers, and 5 of them are green. eSolutions Manual - Powered by Cognero Page 7