54 CHAPTER 2 Descriptive Statistics In Exercises 43 and 44, use the data set and the indicated number of classes to construct (a) an expanded frequency distribution, (b) a frequency histogram, (c) a frequency polygon, (d) a relative frequency histogram, and (e) an ogive. 43. Pulse Rates Number of classes: 6 Data set: Pulse rates of all students in a class 68 105 95 80 90 100 75 70 84 98 102 70 65 88 90 75 78 94 110 120 95 80 76 108 44. Hospitals Number of classes: 8 Data set: Number of hospitals in each of the 50 U.S. states and 5 inhabited territories (Source: American Hospital Directory) 10 90 51 1 77 341 56 34 8 214 111 3 14 40 18 142 102 55 75 108 72 53 19 105 55 83 1 69 19 108 10 27 14 78 37 31 186 146 90 37 177 52 11 67 25 100 361 35 91 2 7 61 78 33 14 Extending Concepts 45. What Would You Do? You work at a bank and are asked to recommend the amount of cash to put in an ATM each day. You do not want to put in too much (which would cause security concerns) or too little (which may create customer irritation). The daily withdrawals (in hundreds of dollars) for 30 days are listed. 72 84 61 76 104 76 86 92 80 88 98 76 97 82 84 67 70 81 82 89 74 73 86 81 85 78 82 80 91 83 (a) Construct a relative frequency histogram for the data. Use 8 classes. (b) If you put $9000 in the ATM each day, what percent of the days in a month should you expect to run out of cash? Explain. (c) If you are willing to run out of cash on 10% of the days, how much cash should you put in the ATM each day? Explain. 46. What Would You Do? The admissions department for a college is asked to recommend the minimum SAT scores that the college will accept for full-time students. The SAT scores of 50 applicants are listed. 1170 1000 910 870 1070 1290 920 1470 1080 1180 770 900 1120 1070 1370 1160 970 930 1240 1270 1250 1330 1010 1010 1410 1130 1210 1240 960 820 650 1010 1190 1500 1400 1270 1310 1050 950 1150 1450 1290 1310 1100 1330 1410 840 1040 1090 1080 (a) Construct a relative frequency histogram for the data. Use 10 classes. (b) If you set the minimum score at 1070, what percent of the applicants will meet this requirement? Explain. (c) If you want to accept the top 88% of the applicants, what should the minimum score be? Explain. 47. Writing Use the data set listed and technology to create frequency histograms with 5, 10, and 20 classes. Which graph displays the data best? Explain. 2 7 3 2 11 3 15 8 4 9 10 13 9 7 11 10 1 2 12 5 6 4 2 9 15 14
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