HW1_Chpt8_exercises

HW1_Chpt8_exercises - “sting inter- : 32. te the (8-20)...

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Unformatted text preview: “sting inter- : 32. te the (8-20) tedian . 5 class e, say (8-21) st fre- ss and :n the "':.‘r.‘| -' - . ons of ore. :1 1(2thle 1116811. ldevi- ' 1 ’more. (Ines-s. linear ample he dot 5 8-6 EXERCISES 8-1. The shelf life of a high-speed photographic film is being investigated by the manufacturer. The following data are available. R Life Life Life Life (days) (days) (days) (days) 126 I29 134 I41 131 132 136 145 116 128 I30 I62 125 126 I34 I29 I34 127 I20 127 I20 122 129 I33 125 l 11 I47 129 150 148 126 140 130 120 I I7 I31 I49 l 17 143 133 E Construct a histogram and comment on the properties of the data. 8-2. The percentage of cotton in a material used to manufacture men's shirts is given below. Construct a histogram for the data. Comment on the properties of the data. X 34.2 33.6 33.8 34.7 37.8 32.6 35.8 34.6 33.1 34.7 34.2 33.6 36.6 33.1 37.6 33.6 34.5 35.0 33.4 32.5 35.4 34.6 37.3 34.1 35.6 35.4 34.7 34.1 34.6 35.9 34.6 34.7 34.3 36.2 34.6 35.1 33.8 34.7 35.5 35.7 35.1 36.8 35.2 36.8 37.1 33.6 32.8 36.8 14.7 35.1 35.0 37.9 34.0 32.9 32.1 34.3 33.6 35.3 34.9 36.4 34.1 33.5 34.5 32.7 R 8-3. The following data represent the yield on 90 con- wcutive batches of ceramic substrate to which a metal coating has been applied by a vapor»deposition process. Construct a histogram for these data and comment on the properties of the data. X 94.1 87.3 94.1 92.4 84.6 85.4 93.2 84.1 92.1 90.6 83.6 86.6 90.6 90.1 96.4 89.1 85.4 9 I .7 91.4 95.2 88.2 88.8 89.7 87.5 88.2 86.1 86.4 86.4 87.6 84.2 86.1 94.3 85.0 85.1 85.1 85.1 95.1 93.2 84.9 84.0 89.6 90.5 90.0 86.7 87.3 93.7 90.0 95.6 92.4 83.0 89.6 87.7 90.1 88.3 87.3 95.3 90.3 90.6 94.3 84.1 8-6 Exercises 193 86.6 94.1 93.1 89.4 97.3 83.7 91.2 97.8 94.6 88.6 96.8 82.9 86.1 93.1 96.3 84.1 94.4 87.3 90.4 86.4 94.7 82.6 96.1 86.4 89.1 87.6 91.1 83.1 98.0 84.5 x 8-4. An electronics company manufactures power supplies for a personal computer. They produce scv- cral hundred power supplies each shift. and each unit is subjected to a lZ-hour burn-in test. The number of units failing during this l2»hour test each shift is shown below. (a) Construct a frequency distribution and histogram. (b) Find the sample mean. sample variance. and sam- ple standard deviation. 3 6 4 7 6 7 4 7 8 2 l 4 2 9 4 6 4 8 5 10 10 9 l3 7 6 l4 I4 10 I2 3 IO 13 8 7 10 6 5 10 12 9 2 7 4 9 4 l6 5 8 3 8 5 ll 7 4 ll 10 l4 I3 10 I2 9 3 .. 3 4 6 2 2 8 l3 2 l7 7 4 6 3 2 5 8 6 IO 7 6 10 4 4 8 3 4 8 2 10 6 2 10 9 6 8 4 9 8 ll 5 7 6 4 l4 7 4 I4 [5 l3 6 2 3 l3 4 3 4 8 2 12 7 4 10 8 5 5 5 8 7 10 4 3 10 7 4 9 6 2 6 9 3 ll 5 6 7 2 6 1 8-5. Consider the shelf life data in Exercise 8- I. Com- pute the sample mean. sample variance. and sample standard deviation. 8-6. Consider the cotton percentage data in Exercise 8-2. Find the sample mean. sample variance. sample standard deviation. sample ntcdian. and sample mode. 194 Chapter 8 Introduction to Statistics and Data Description 8-7. Consider the yield data in Exercise 8-3. Calculate the sample mean, sample variance. and sample stan- dard deviation. 8-8. An article in Computers and Industrial Engineer- ing (2001. p. 5 1) describes the time-to-t‘ailure data (in hours) for jet engines. Some of the data are repro- duced below. Failure Failure Engine # Time Engine # Time 1 150 14 171 2 291 15 197 3 93 16 200 4 53 17 262 5 2 18 255 6 65 19 286 7 183 20 206 8 144 21 179 9 223 22 232 10 197 23 165 l l 187 24 155 12 197 25 203 13 213 (a) Construct a frequency distribution and histogram for these data. (b) Calculate the sample mean. sample median. sam- ple variance, and sample standard deviation. 8-9. For the time-to—failure data in Exercise 8-8. sup- pose the fifth observation (2 hours) is discarded. Con- struct a frequency distribution and a histogram for the remaining data. and calculate the sample mean. sam- ple median, sample variance. and sample standard deviation. Compare the results with those obtained in Exercise 8-8. What impact has removal of this obser- vation had on the summary statistics? 8-10. An article in Tecltnometrics (Vol. 19. 1977. p. 425) presents the following data on motor fuel octane ratings of several blends of gasoline: 88.5, 87.7. 83.4. 86.7. 87.5. 91.5. 88.6. 100.3. 95.6. 93.3, 94.7. 91.1, 91.0. 94.2. 87.8. 89.9. 88.3. 87.6. 84.3. 86.7, 88.2, 90.8. 88.3. 98.8. 94.2. 92.7, 93.2. 91.0, 90.3. 93.4, 88.5. 90.1. 89.2, 88.3. 85.3. 87.9. 88.6. 90.9. 89.0, 96.1, 93.3. 91.8. 92.3. 90.4, 90.1. 93.0. 88.7, 89.9, 89.8. 89.6, 87.4. 88.4, 88.9. 91.2. 89.3, 94.4, 92.7. 91.8. 91.6. 90.4. 91.1. 92.6. 89.8, 90.6. 91.1. 90.4. 89.3. 89.7. 90.3. 91.6. 90.5. 93.7, 92.7. 92.2. 92.2. 91.2. 91.0. 92.2. 90.0. 90.7. (a) Construct a stem-and-leaf plot. (b) Construct a frequency distribution and histogram. (c) Calculate the sample mean. sample variance, and sample standard deviation. (d) Find the sample median and sample mode. (e) Determine the skewness and kurtosis measures. 8-11. Consider the shelf-life data in Exercise 8-1. Construct a stem-and-leaf plot for these data. Con- struct an ordered stem-and-leaf plot. Use this plot to find the 65th and 95th percentiles. 8-12. Consider the cotton percentage data in Exercise 82 (a) Construct a stem-and-leaf plot. (b) Calculate the sample mean. sample variance. and sample standard deviation. (c) Construct an ordered stem-and-leaf plot. (d) Find the median and the first and third quartiles. (c) Find the interquartile range. (1) Determine the skewness and kurtosis measures. 8-13. Consider the yield data in Exercise 8-3. (a) Construct an ordered stem-and-leaf plot. (b) Find the median and the first and third quartiles. (c) Calculate the interquartile range. 8-14. Construct a box plot for the shelf-life data in Exercise 8-1. Interpret the data using this plot. 8-15. Construct a box plot for the cotton percentage data in Exercise 8-2. Interpret the data using this plot. 8-16. Construct a box plot for the yield data in Exer- cise 8-3. Compare it to the histogram (Exercise 8-3) and the stem-and-leaf plot (Exercise 8-13). Interpret the data. 8-17. An article in the Electrical Manufizcmring & Coil Winding Conference Proceedings (1995, p. 829) presents the results for the number of returned ship- ments for a record-of-the-month club. The company is interested in the reason for a returned shipment. The results are shown below. Construct a Pareto chart and interpret the data. Reason Number of Customers Refused 195,000 Wrong selection 50.000 Wrong answer 68.000 Canceled 5.000 Other 15.000 8-18. The following tal: occurrence of final lette Joumal. Construct a his any of the numerical de; any meaning for these dz 12 1 1 ll 20 25 a b C a e r g 12 h i j k 1 m 8-19. Show the following (a) That 27:10:. —f) :1 w (b) That (x, —_r) = 8-20. The weight of beari process is being investigate provided the weights 1.18. l.2l pounds. Find the sam sample standard deviation. 8-21. The diameter of eigh shown below. Calculate variance. and sample stand 74.001 mm 74.005 74.003 74.001 8-22. The thickness of prin important characteristic. A the following thicknesses 63. 61. 65. 62. 61. 64. 60. at mean, sample variance. and What are the units of meast 8-23. Coding the Data. C hoard thickness data in Exe (a) Suppose that we subtrat number. How are the s ance. and sample stand (b) Suppose that we multi How are the sample ml sample standard deviati ...
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This note was uploaded on 01/04/2011 for the course ISE 31602D taught by Professor Kurtpalmer during the Fall '10 term at USC.

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HW1_Chpt8_exercises - “sting inter- : 32. te the (8-20)...

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