Page 241 - Applied Statistics And Probability For Engineers

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202 CHAPTER 6 RANDOM SAMPLING AND DATA DESCRIPTION

6-18. Find the median and the quartiles for the motor fuel distance test is conducted by hitting balls with a driver swung
octane data in Exercise 6-14. by a mechanical device nicknamed “Iron Byron” after the
6-19. Find the median and the quartiles for the failure data legendary great Byron Nelson, whose swing the machine is said
in Exercise 6-15. to emulate. Following are 100 distances (in yards) achieved by
a particular brand of golf ball in the overall distance test.
6-20. Find the median, mode, and sample average of the
data in Exercise 6-16. Explain how these three measures of Construct a stem-and-leaf diagram for this data and comment
location describe different features in the data. on any important features that you notice. Compute the sample
mean, sample standard deviation, and the sample median.
6-21. Find the median and the quartiles for the yield data in
Exercise 6-19. 261.3 259.4 265.7 270.6 274.2 261.4 254.5 283.7
6-22. The female students in an undergraduate engineering 258.1 270.5 255.1 268.9 267.4 253.6 234.3 263.2
core course at ASU self-reported their heights to the nearest 254.2 270.7 233.7 263.5 244.5 251.8 259.5 257.5
inch. The data are 257.7 272.6 253.7 262.2 252.0 280.3 274.9 233.7
62 64 66 67 65 68 61 65 67 65 64 63 67 237.9 274.0 264.5 244.8 264.0 268.3 272.1 260.2
68 64 66 68 69 65 67 62 66 68 67 66 65 255.8 260.7 245.5 279.6 237.8 278.5 273.3 263.7
69 65 70 65 67 68 65 63 64 67 67 241.4 260.6 280.3 272.7 261.0 260.0 279.3 252.1
244.3 272.2 248.3 278.7 236.0 271.2 279.8 245.6
(a) Calculate the sample mean and standard deviation of 241.2 251.1 267.0 273.4 247.7 254.8 272.8 270.5
height.
(b) Construct a stem-and-leaf diagram for the height data and 254.4 232.1 271.5 242.9 273.6 256.1 251.6
comment on any important features that you notice. 256.8 273.0 240.8 276.6 264.5 264.5 226.8
(c) What is the median height of this group of female engi- 255.3 266.6 250.2 255.8 285.3 255.4 240.5
neering students? 255.0 273.2 251.4 276.1 277.8 266.8 268.5
6-23. The shear strengths of 100 spot welds in a titanium 6-26. A semiconductor manufacturer produces devices used
alloy follow. Construct a stem-and-leaf diagram for the weld as central processing units in personal computers. The speed of
strength data and comment on any important features that you the device (in megahertz) is important because it determines the
notice. price that the manufacturer can charge for the devices. The fol-
5408 5431 5475 5442 5376 5388 5459 5422 5416 5435 lowing table contains measurements on 120 devices. Construct a
5420 5429 5401 5446 5487 5416 5382 5357 5388 5457 stem-and-leaf diagram for this data and comment on any impor-
5407 5469 5416 5377 5454 5375 5409 5459 5445 5429 tant features that you notice. Compute the sample mean, sample
standard deviation, and the sample median. What percentage of
5463 5408 5481 5453 5422 5354 5421 5406 5444 5466
the devices has a speed exceeding 700 megahertz?
5399 5391 5477 5447 5329 5473 5423 5441 5412 5384
5445 5436 5454 5453 5428 5418 5465 5427 5421 5396 680 669 719 699 670 710 722 663 658 634 720 690
5381 5425 5388 5388 5378 5481 5387 5440 5482 5406 677 669 700 718 690 681 702 696 692 690 694 660
5401 5411 5399 5431 5440 5413 5406 5342 5452 5420 649 675 701 721 683 735 688 763 672 698 659 704
5458 5485 5431 5416 5431 5390 5399 5435 5387 5462 681 679 691 683 705 746 706 649 668 672 690 724
5383 5401 5407 5385 5440 5422 5448 5366 5430 5418 652 720 660 695 701 724 668 698 668 660 680 739
717 727 653 637 660 693 679 682 724 642 704 695
6-24. An important quality characteristic of water is the con-
centration of suspended solid material. Following are 60 meas- 704 652 664 702 661 720 695 670 656 718 660 648
urements on suspended solids from a certain lake. Construct a 683 723 710 680 684 705 681 748 697 703 660 722
stem-and-leaf diagram for this data and comment on any im- 662 644 683 695 678 674 656 667 683 691 680 685
portant features that you notice. Compute the sample mean, 681 715 665 676 665 675 655 659 720 675 697 663
sample standard deviation, and the sample median.
6-27. A group of wine enthusiasts taste-tested a pinot noir
42.4 65.7 29.8 58.7 52.1 55.8 57.0 68.7 67.3 67.3 wine from Oregon. The evaluation was to grade the wine on a
54.3 54.0 73.1 81.3 59.9 56.9 62.2 69.9 66.9 59.0 0 to 100 point scale. The results follow:
56.3 43.3 57.4 45.3 80.1 49.7 42.8 42.4 59.6 65.8
61.4 64.0 64.2 72.6 72.5 46.1 53.1 56.1 67.2 70.7 94 90 92 91 91 86 89 91 91 90
42.6 77.4 54.7 57.1 77.3 39.3 76.4 59.3 51.1 73.8 90 93 87 90 91 92 89 86 89 90
61.4 73.1 77.3 48.5 89.8 50.7 52.0 59.6 66.1 31.6 88 95 91 88 89 92 87 89 95 92
6-25. The United States Golf Association tests golf balls to 85 91 85 89 88 84 85 90 90 83
ensure that they conform to the rules of golf. Balls are tested for (a) Construct a stem-and-leaf diagram for this data and com-
weight, diameter, roundness, and overall distance. The overall ment on any important features that you notice.