QA 233 (Basic Business Statistics)
Case Assignments
Case 1
A “Boring” Time
Jon Weideman, first shift foreman for Cut-Rate Machining, Inc., is attempting to decide which vendor from whom to purchase a drilling machine. He narrows his alternatives to four vendors: The Hole-Maker, Inc. (HM); Shafts & Slips, Inc. (SS); Judge’s Jigs (JJ); and Drill For Bits, Inc. (DB). Each of these vendors is offering machines of similar capabilities at similar prices, so the effectiveness of the machines is the only selection criteria that Mr. Weideman can use. He invites each vendor to ship one machine to his Richmond, Indiana manufacturing facility for a test. He starts all four machines at 8:00 a.m. and lets them warm up for two hours, at which point one of his employees will use each of the shipped machines to drill 3 inch diameter holes in 6 inch thick stainless steel sheets for two hours. The width of holes drilled with each machine are then measured and recorded. The results of Mr. Weideman’s data collection follow.
|
Hole
# |
Hole
Maker |
Shafts
& Slips |
Judge's
Jigs |
Drill
for Bits |
|
1 |
3.15536 |
2.92252 |
2.60190 |
2.02030 |
|
2 |
2.99755 |
2.97392 |
2.60222 |
3.03385 |
|
3 |
3.08858 |
2.98229 |
2.59763 |
3.32224 |
|
4 |
3.18197 |
2.79168 |
2.60185 |
2.00025 |
|
5 |
3.14757 |
2.96214 |
2.60190 |
2.25248 |
|
6 |
3.12699 |
2.95743 |
2.59802 |
3.76329 |
|
7 |
2.93129 |
2.82490 |
2.60037 |
3.41679 |
|
8 |
3.19791 |
2.81727 |
2.59538 |
2.87640 |
|
9 |
3.20484 |
2.88561 |
2.60014 |
1.91941 |
|
10 |
3.04455 |
2.84558 |
2.59620 |
3.21901 |
|
11 |
3.19053 |
2.94179 |
2.60091 |
3.67859 |
|
12 |
3.11642 |
2.82028 |
2.60332 |
2.87002 |
|
13 |
3.18062 |
2.93314 |
2.60095 |
3.07564 |
|
14 |
3.17639 |
2.82812 |
2.60779 |
3.35902 |
|
15 |
3.13445 |
2.88686 |
2.59097 |
2.55533 |
|
16 |
3.10877 |
2.99191 |
2.61027 |
3.74159 |
|
17 |
3.16878 |
2.91444 |
2.59583 |
2.85352 |
|
18 |
3.14210 |
2.88477 |
2.60213 |
2.94686 |
|
19 |
3.06593 |
2.93674 |
2.59981 |
3.53161 |
|
20 |
3.06655 |
2.88121 |
2.60558 |
2.74854 |
|
21 |
2.95824 |
2.84613 |
2.60617 |
2.76577 |
|
22 |
3.01954 |
2.92180 |
2.60244 |
1.77106 |
|
23 |
2.82097 |
3.06028 |
2.60703 |
1.36567 |
|
24 |
3.13009 |
2.89668 |
2.59533 |
4.58108 |
|
25 |
3.01082 |
2.96004 |
2.59734 |
3.95579 |
|
26 |
2.96001 |
2.95365 |
2.59312 |
3.49077 |
|
27 |
3.11984 |
2.92686 |
2.59359 |
2.40779 |
|
28 |
2.99894 |
2.86093 |
2.61020 |
2.65877 |
|
29 |
3.26797 |
2.88655 |
2.60677 |
2.79807 |
|
30 |
2.98131 |
2.99421 |
2.60152 |
3.12367 |
|
31 |
3.03523 |
2.82062 |
2.59805 |
2.61922 |
|
32 |
3.18298 |
2.96640 |
2.60490 |
4.39890 |
|
33 |
3.14620 |
2.94228 |
2.60683 |
4.22789 |
|
34 |
3.16456 |
2.91600 |
2.59663 |
2.89872 |
|
35 |
3.15434 |
2.97500 |
2.59056 |
2.76578 |
|
36 |
3.16014 |
2.92051 |
2.60189 |
3.26863 |
|
37 |
3.05647 |
2.79988 |
2.59981 |
3.80914 |
|
38 |
3.17880 |
2.83380 |
2.60374 |
2.34738 |
|
39 |
3.21182 |
2.83800 |
2.60643 |
3.54851 |
|
40 |
3.12614 |
2.81183 |
2.60085 |
1.76834 |
|
41 |
3.21445 |
2.87817 |
2.59782 |
3.11172 |
|
42 |
3.09201 |
2.96431 |
2.60416 |
2.78681 |
|
43 |
3.19941 |
2.90182 |
2.60136 |
3.67875 |
|
44 |
3.14182 |
2.91667 |
2.59764 |
1.48390 |
|
45 |
2.94660 |
2.90583 |
2.60185 |
1.19745 |
|
46 |
3.17295 |
3.02606 |
2.60181 |
2.52600 |
|
47 |
3.04423 |
2.76927 |
2.60122 |
2.98701 |
|
48 |
3.07935 |
2.88717 |
2.59803 |
2.83613 |
|
49 |
3.00184 |
2.85111 |
2.59865 |
2.92475 |
|
50 |
3.18056 |
2.91170 |
2.59742 |
2.32291 |
|
51 |
2.99621 |
2.88600 |
2.59890 |
3.94451 |
|
52 |
3.05767 |
2.95688 |
2.59823 |
3.24739 |
|
53 |
2.99594 |
2.85948 |
2.60566 |
2.20663 |
|
54 |
3.00732 |
2.95893 |
2.60036 |
2.95989 |
|
55 |
3.13596 |
2.90924 |
2.59107 |
2.51437 |
|
56 |
3.02220 |
2.77657 |
2.59610 |
3.59299 |
|
57 |
3.25144 |
2.98844 |
2.59619 |
2.61903 |
|
58 |
3.16287 |
2.85970 |
2.59501 |
2.85114 |
|
59 |
3.25185 |
2.90787 |
2.59504 |
3.13359 |
|
60 |
3.09615 |
2.92056 |
2.60343 |
4.56557 |
|
61 |
3.11892 |
2.96387 |
2.59397 |
4.26472 |
|
62 |
2.94550 |
2.89802 |
2.60354 |
2.39693 |
|
63 |
3.07938 |
2.93147 |
2.60579 |
3.48364 |
|
64 |
2.98800 |
2.95297 |
2.59897 |
4.29441 |
|
65 |
3.11029 |
2.91004 |
2.60483 |
4.31025 |
|
66 |
3.01084 |
2.91917 |
2.60742 |
2.41979 |
|
67 |
2.90110 |
3.00518 |
2.60799 |
2.94662 |
|
68 |
3.04483 |
2.94290 |
2.60358 |
2.78153 |
|
69 |
3.08349 |
2.91355 |
2.59818 |
2.75056 |
|
70 |
3.22777 |
2.92246 |
2.60281 |
2.65155 |
|
71 |
3.14054 |
2.91922 |
2.59500 |
2.14858 |
|
72 |
2.95388 |
2.90369 |
2.61360 |
3.01557 |
|
73 |
3.02436 |
2.94998 |
2.60326 |
3.73582 |
|
74 |
2.91797 |
2.96277 |
2.59861 |
3.49731 |
|
75 |
3.02412 |
2.96588 |
2.60189 |
2.87547 |
|
76 |
3.10228 |
2.83906 |
2.59506 |
2.76278 |
|
77 |
3.09689 |
2.96647 |
2.59990 |
2.84366 |
|
78 |
3.01655 |
2.90445 |
2.60895 |
2.76274 |
|
79 |
3.01571 |
2.77522 |
2.60425 |
2.69899 |
|
80 |
3.13225 |
3.00485 |
2.60059 |
3.72456 |
|
81 |
3.28562 |
2.89425 |
2.60416 |
2.56143 |
|
82 |
3.02413 |
2.99810 |
2.60540 |
2.21533 |
|
83 |
3.14622 |
2.90782 |
2.59611 |
3.79024 |
|
84 |
3.05886 |
2.95759 |
2.59322 |
1.77384 |
|
85 |
3.03722 |
2.91667 |
2.60620 |
2.37768 |
|
86 |
3.18600 |
2.82870 |
2.60411 |
3.01132 |
|
87 |
3.02756 |
2.90239 |
2.59350 |
4.38121 |
|
88 |
3.11614 |
2.79594 |
2.60022 |
3.56086 |
|
89 |
3.22214 |
2.86875 |
2.59440 |
2.30481 |
|
90 |
3.20506 |
2.88447 |
2.60229 |
2.90249 |
|
91 |
3.17946 |
2.95572 |
2.60061 |
1.99928 |
|
92 |
3.13221 |
3.03448 |
2.59475 |
3.34981 |
|
93 |
3.17589 |
2.85118 |
2.59277 |
3.31810 |
|
94 |
3.23455 |
2.91646 |
2.59750 |
4.22752 |
|
95 |
3.13817 |
2.89485 |
2.59887 |
2.57046 |
|
96 |
3.08232 |
3.00038 |
2.59608 |
3.45791 |
|
97 |
2.91372 |
2.88582 |
2.59287 |
2.43684 |
|
98 |
2.98697 |
2.91636 |
2.60048 |
3.30704 |
|
99 |
3.16420 |
2.83932 |
2.60371 |
2.80038 |
|
100 |
3.20602 |
2.88451 |
2.59529 |
2.60546 |
Based on these results, from which vendor would you suggest Mr. Weideman purchase his new machine?
Hint: Think carefully about what qualities would make a drill desirable for Mr. Weideman.
Click here to download an Excel® file containing the raw data used in this case.