Student’s Solutions Manual and Study Guide: Chapter 2 Page 1 Chapter 2 Charts and Graphs LEARNING OBJECTIVES The overall objective of Chapter 2 is for you to master several techniques for summarizing and depicting data, thereby enabling you to: 1. 2. 3. 4. Construct a frequency distribution from a set of data Construct different types of quantitative data graphs, including histograms, frequency polygons, ogives, dot plots, and stem-and-leaf plots, in order to interpret the data being graphed Construct different types of qualitative data graphs, including pie charts, bar graphs, and Pareto charts, in order to interpret the data being graphed Recognize basic trends in two-variable scatter plots of numerical data CHAPTER OUTLINE 2.1 2.2 2.3 2.4 Frequency Distributions Class Midpoint Relative Frequency Cumulative Frequency Quantitative Data Graphs Histograms Frequency Polygons Ogives Dot Plots Stem and Leaf Plots Qualitative Data Graphs Pie Charts Bar Graphs Pareto Charts Graphical Depiction of Two-Variable Numerical Data: Scatter Plots Student’s Solutions Manual and Study Guide: Chapter 2 Page 2 KEY TERMS Bar Graph Class Mark Class Midpoint Cumulative Frequency Dot Plot Frequency Distribution Frequency Polygon Grouped Data Histogram Ogive Pareto Chart Pie Chart Range Relative Frequency Scatter Plot Stem-and-Leaf Plot Ungrouped Data Student’s Solutions Manual and Study Guide: Chapter 2 Page 3 STUDY QUESTIONS 1. The following data represents the number of printer ribbons used annually in a company by twenty-eight departments. This is an example of ______________ data. 8 4 5 10 6 5 4 6 3 4 4 6 1 12 2 11 2 5 3 2 6 7 6 12 7 1 8 9 2. Below is a frequency distribution of ages of managers with a large retail firm. This is an example of _______________ data. Age 20-29 30-39 40-49 50-59 over 60 f 11 32 57 43 18 3. For best results, a frequency distribution should have between _____ and _____ classes. 4. The difference between the largest and smallest numbers is called the _______________. 5. Consider the values below. In constructing a frequency distribution, the beginning point of the lowest class should be at least as small as _____ and the endpoint of the highest class should be at least as large as _____. 27 21 8 10 9 16 11 12 21 11 29 19 17 22 28 28 29 19 18 26 17 34 19 16 20 6. The class midpoint can be determined by _______________. 7-9 Examine the frequency distribution below: class 5-under 10 10-under 15 15-under 20 20-under 25 25-under 30 30-under 35 frequency 56 43 21 11 12 8 7. The relative frequency for the class 15-under 20 is _______________. 8. The cumulative frequency for the class 20-under 25 is _______________. 9. The midpoint for the class 25-under 30 is ___________. Student’s Solutions Manual and Study Guide: Chapter 2 Page 4 10. The graphical depiction that is a type of vertical bar chart and is used to depict a frequency distribution is a _______________. 11. The graphical depiction that utilizes cumulative frequencies is a _______________. 12. The graph shown below is an example of a _______________. 13. Consider the categories below and their relative amounts: Category A B C D E Amount 112 319 57 148 202 If you were to construct a Pie Chart to depict these categories, then you would allot _______________ degrees to category D. 14. A graph that is especially useful for observing the overall shape of the distribution of data points along with identifying data values or intervals for which there are groupings and gaps in the data is called a ______________________. 15. Given the values below, construct a stem and leaf plot using two digits for the stem. 346 340 322 339 342 332 338 357 328 329 346 341 321 332 16. A vertical bar chart that displays the most common types of defects that occur with a product, ranked in order from left to right, is called a __________________. 17. A two-dimensional plot of pairs of points often used to examine the relationship of two numerical variables is called a _________________. Student’s Solutions Manual and Study Guide: Chapter 2 Page 5 ANSWERS TO STUDY QUESTIONS 1. Raw or Ungrouped 10. Histogram 2. Grouped 11. Ogive 3. 5, 15 12. Frequency Polygon 4. Range 13. 148/838 of 360o = 63.6o 5. 8, 34 14. Dot Plot 6. Averaging the two class endpoints 15. 32 33 34 35 7. 21/151 = .1391 1 2 8 9 2 2 8 9 0 1 2 6 6 7 8. 131 16. Pareto Chart 9. 27.5 17. Scatter Plot Student’s Solutions Manual and Study Guide: Chapter 2 Page 6 SOLUTIONS TO PROBLEMS IN CHAPTER 2 2.1 a) One possible 5 class frequency distribution: Class Interval 0 - under 20 20 - under 40 40 - under 60 60 - under 80 80 - under 100 b) One possible 10 class frequency distribution: Class Interval 10 - under 18 18 - under 26 26 - under 34 34 - under 42 42 - under 50 50 - under 58 58 - under 66 66 - under 74 74 - under 82 82 - under 90 c) Frequency 7 15 12 12 4 50 Frequency 7 3 5 9 7 3 6 4 4 2 The ten class frequency distribution gives a more detailed breakdown of temperatures, pointing out the smaller frequencies for the higher temperature intervals. The five class distribution collapses the intervals into broader classes making it appear that there are nearly equal frequencies in each class. Student’s Solutions Manual and Study Guide: Chapter 2 Page 7 2.3 Class Interval Frequency 0-5 6 5 - 10 8 10 - 15 17 15 - 20 23 20 - 25 18 25 - 30 10 30 - 35 4 TOTAL 86 Class Midpoint 2.5 7.5 12.5 17.5 22.5 27.5 32.5 Relative Frequency 6/86 = .0698 .0930 .1977 .2674 .2093 .1163 .0465 1.0000 Cumulative Frequency 6 14 31 54 72 82 86 The relative frequency tells us that it is most probable that a customer is in the 15 - 20 category (.2674). Over two thirds (.6744) of the customers are between 10 and 25 years of age. 2.5 Some examples of cumulative frequencies in business: sales for the fiscal year, costs for the fiscal year, spending for the fiscal year, inventory build-up, accumulation of workers during a hiring buildup, production output over a time period. Student’s Solutions Manual and Study Guide: Chapter 2 2.7 Histogram: Frequency Polygon: Page 8 Student’s Solutions Manual and Study Guide: Chapter 2 2.9 STEM LEAF 21 22 23 24 25 26 27 2.11 Page 9 2 0 0 0 0 0 0 8 1 0 0 3 1 1 8 2 4 3 4 1 3 9 4 5 6 5 2 6 8 9 5 3 Firm Caterpillar Deere Illinois Too Works Eaton American Standard TOTAL 6 8 9 7 3 7 9 9 7 5 9 9 9 9 9 8 9 6 Proportion Degrees .372 .246 .144 .121 .117 1.000 134 89 52 44 42 361 Pie Chart: Annual Sales American Standard 12% Eaton 12% Caterpillar 37% Illinois Tool Works 14% Deere 25% Student’s Solutions Manual and Study Guide: Chapter 2 Page 10 Bar Graph: Chart of Revenue 30000 25000 Revenue 20000 15000 10000 5000 0 2.13 Caterpillar Deere Illinois Tool Works Eaton Equipment Companies Brand Pfizer Johnson & Johnson Merck Bristol-Myers Squibb Abbott Laboratories Wyeth TOTAL Pie Chart: Proportion .289 .259 .125 .120 .112 .095 1.000 American Standard Degrees 104 93 45 43 40 34 359 Student’s Solutions Manual and Study Guide: Chapter 2 Page 11 Pharmaceutical Sales Wyeth 9% Pfizer 29% Abbott Lab. 11% Bristol-Myers Squibb 12% Merck 13% Johnson & Johnson 26% Bar Graph: Chart of Sales 60000 50000 Sales 40000 30000 20000 10000 0 r ize f P on ns h Jo & n so n h Jo M ck er s er b ib u Sq y -M l to is Br Phar. Co. r bo a tL ot b Ab ie or t a s W th ye Student’s Solutions Manual and Study Guide: Chapter 2 Page 12 2.15 3500 3000 Industrial Products 2500 2000 1500 1000 500 0 0 1000 2000 3000 4000 5000 6000 7000 Human Food Generally, as the amount of fish caught for human consumption increases, the amount used for industrial products tends to decrease. 2.17 Class Interval Frequencies 16 - under 23 23 - under 30 30 - under 37 37 - under 44 44 - under 51 51 - under 58 TOTAL 6 9 4 4 4 3 30 Student’s Solutions Manual and Study Guide: Chapter 2 2.19 Page 13 Class Interval Frequencies 50 - under 60 60 - under 70 70 - under 80 80 - under 90 90 - under 100 TOTAL 13 27 43 31 9 123 Histogram: Student’s Solutions Manual and Study Guide: Chapter 2 Frequency Polygon: Ogive: Page 14 Student’s Solutions Manual and Study Guide: Chapter 2 2.21 STEM LEAF 28 29 30 31 32 33 2.23 Page 15 4 0 1 1 4 5 6 4 6 2 4 9 8 8 9 4 6 7 7 6 Bar Graph: Category A B C D E Frequency 7 12 14 5 19 20 Frequency 15 10 5 0 A B C Category D E Student’s Solutions Manual and Study Guide: Chapter 2 Page 16 2.25 16 14 12 Y 10 8 6 4 2 0 0 2 4 6 8 10 12 14 16 18 X 2.27 Class Interval 20 – 25 25 – 30 30 – 35 35 – 40 40 – 45 45 – 50 TOTAL Frequency 8 6 5 12 15 7 53 Class Midpoint 22.5 27.5 32.5 37.5 42.5 47.5 Relative Frequency 8/53 = .1509 .1132 .0943 .2264 .2830 .1321 .9999 Cumulative Frequency 8 14 19 31 46 53 Student’s Solutions Manual and Study Guide: Chapter 2 2.29 Page 17 Frequency Distribution: Class Interval 10 - under 20 20 - under 30 30 - under 40 40 - under 50 50 - under 60 60 - under 70 70 - under 80 80 - under 90 Histogram: Frequency 2 3 9 7 12 9 6 2 50 Student’s Solutions Manual and Study Guide: Chapter 2 Page 18 Frequency Polygon: The normal distribution appears to peak near the center and diminish towards the end intervals. Student’s Solutions Manual and Study Guide: Chapter 2 2.31 Amount Spent on Prenatal Care $ 0 - under $100 $100 - under $200 $200 - under $300 $300 - under $400 $400 - under $500 $500 - under $600 Histogram: Page 19 Frequency 3 6 12 19 11 6 57 Cumulative Frequency 3 9 21 40 51 57 Student’s Solutions Manual and Study Guide: Chapter 2 Frequency Polygon: Ogive: Page 20 Student’s Solutions Manual and Study Guide: Chapter 2 2.33 Genre R&B Alternative Rap Country Soundtrack Metal Classical Latin TOTAL Page 21 Albums Sold 146.4 102.6 73.7 64.5 56.4 26.6 14.8 14.5 Proportion .29 .21 .15 .13 .11 .05 .03 .03 1.00 Degrees 104 76 54 47 40 18 11 11 361 Pie Chart: Classical 3% Metal 5% Soundtrack 11% Latin 3% R&B 29% Country 13% Rap 15% Alternative 21% Student’s Solutions Manual and Study Guide: Chapter 2 Page 22 Bar Chart: 160 140 Albums Sold 120 100 80 60 40 20 0 R&B Alternative Rap Country Soundtrack Genre Metal Classical Latin Student’s Solutions Manual and Study Guide: Chapter 2 Page 23 2.35 Industry Total Release Proportion Degrees Chemicals Primary metals Paper Plastics & Rubber Transportation Equipment Food Fabricated Metals Petroleum Electrical Equipment 737,100,000 566,400,000 229,900,000 109,700,000 .366 .281 .114 .054 132 103 41 19 102,500,000 89,300,000 85,900,000 63,300,000 .051 .044 .043 .031 18 16 15 11 29,100,000 .014 5 0.998 360 TOTAL Pie Chart: Fab. Metals 4% Food 4% Petro. Elec. 3% 1% Trans. Equip. 5% Chem. 38% Plas. & Rubber 5% Paper 11% Prim. Metals 29% Student’s Solutions Manual and Study Guide: Chapter 2 Page 24 Bar Graph: 800000000 700000000 Release 600000000 500000000 400000000 300000000 200000000 100000000 0 em Ch s al ic im Pr ar y al et M s r pe a P s ti c as l P d an r be b Ru Tr s. an m ip u Eq t en od Fo F Industry d te a c ri ab s al et M Pe um le o tr . ec El t en m p ui Eq Student’s Solutions Manual and Study Guide: Chapter 2 2.37 STEM 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 LEAF 12 16 04 28 20 40 12 53 54 30 34 22 34 63 48 49 66 21 54 38 66 31 78 56 69 37 50 31 32 19 23 Page 25 24 32 99 99 39 46 61 88 59 58 66 78 90 57 63 91 66 58 73 2.39 There is an especially heavy concentration of values between about 24 and 33. There is somewhat of a gap between 18 and 24 but an especially large gap between 52 and 66. Sixty-six appears to be an outlier. 2.41 The fewest number of audits is 12 and the most is 42. More companies (8) performed 27 audits than any other number. Thirty-five companies performed between 12 and 19 audits. Only 7 companies performed 40 or more audits.