Question

Your firm works in construction and buys ASTM A325M8S bolts in very large numbers. You are interested in purchasing bolts from different suppliers and have obtained and tested samples of 200 bolts from three suppliers: Allnutt, Boltzman, Coachers.You have tested these in your new bolt testing machine, purchased after you had discovered your old bolt testing machine was performing erratically. (For the purposes of this question, you are safe to assume that the new machine works perfectly and that its results are in MPa.)

Your firm wants to ensure that the tensile strengths of the bolts it buys are

- as high as possible

- as consistent as possible (i.e., the variability of bolt strengths is as low as possible)

It is critical that the tensile strength of these bolts exceeds 830MPa.

You should draw on the unit content concerning summary statistics to answer this question.

On the basis of the measurements recorded in Bolts.csv, which supplier (if any) would you recommend, and why?
(Provide any code or visualisations you use to justify your response in Matlab or Python)

Bolts.csv

ID	Manufacturer	Strength
1	Allnutt	852.6157
2	Allnutt	852.3152
3	Allnutt	846.7377
4	Allnutt	846.6087
5	Allnutt	839.9689
6	Allnutt	853.985
7	Allnutt	854.856
8	Allnutt	850.1994
9	Allnutt	858.1238
10	Allnutt	851.5812
11	Allnutt	847.7137
12	Allnutt	854.737
13	Allnutt	855.8812
14	Allnutt	849.6327
15	Allnutt	850.6223
16	Allnutt	858.2869
17	Allnutt	857.9041
18	Allnutt	839.0036
19	Allnutt	841.9916
20	Allnutt	851.3458
21	Allnutt	859.7786
22	Allnutt	855.4899
23	Allnutt	852.3816
24	Allnutt	850.822
25	Allnutt	854.4381
26	Allnutt	851.9055
27	Allnutt	856.2855
28	Allnutt	854.8464
29	Allnutt	850.5259
30	Allnutt	851.5536
31	Allnutt	847.8755
32	Allnutt	848.1497
33	Allnutt	855.4785
34	Allnutt	860.8187
35	Allnutt	852.6602
36	Allnutt	852.2717
37	Allnutt	849.9753
38	Allnutt	851.4164
39	Allnutt	848.8806
40	Allnutt	852.8956
41	Allnutt	854.734
42	Allnutt	849.1007
43	Allnutt	849.9139
44	Allnutt	848.2201
45	Allnutt	846.4107
46	Allnutt	852.122
47	Allnutt	849.6361
48	Allnutt	851.2019
49	Allnutt	853.7438
50	Allnutt	853.0614
51	Allnutt	850.3611
52	Allnutt	853.51
53	Allnutt	848.4284
54	Allnutt	853.0106
55	Allnutt	851.5867
56	Allnutt	851.5966
57	Allnutt	850.372
58	Allnutt	845.8201
59	Allnutt	848.8542
60	Allnutt	853.4202
61	Allnutt	858.7212
62	Allnutt	852.1128
63	Allnutt	844.744
64	Allnutt	863.8724
65	Allnutt	854.9202
66	Allnutt	852.5826
67	Allnutt	854.7914
68	Allnutt	850.2944
69	Allnutt	851.4839
70	Allnutt	851.784
71	Allnutt	854.285
72	Allnutt	857.673
73	Allnutt	844.2713
74	Allnutt	849.8448
75	Allnutt	847.5104
76	Allnutt	848.308
77	Allnutt	844.0275
78	Allnutt	848.2352
79	Allnutt	851.2974
80	Allnutt	852.0845
81	Allnutt	853.6174
82	Allnutt	851.0153
83	Allnutt	860.3356
84	Allnutt	851.8197
85	Allnutt	847.031
86	Allnutt	860.1783
87	Allnutt	843.5853
88	Allnutt	855.473
89	Allnutt	858.4707
90	Allnutt	853.1898
91	Allnutt	845.0044
92	Allnutt	843.3849
93	Allnutt	853.0539
94	Allnutt	856.0759
95	Allnutt	850.2476
96	Allnutt	848.0067
97	Allnutt	852.5038
98	Allnutt	853.8302
99	Allnutt	848.9955
100	Allnutt	848.414
101	Allnutt	844.224
102	Allnutt	847.1632
103	Allnutt	848.7802
104	Allnutt	852.6418
105	Allnutt	854.089
106	Allnutt	847.4136
107	Allnutt	849.7658
108	Allnutt	857.2709
109	Allnutt	852.1755
110	Allnutt	852.3071
111	Allnutt	849.8271
112	Allnutt	856.8335
113	Allnutt	855.1246
114	Allnutt	844.2614
115	Allnutt	852.3047
116	Allnutt	847.8268
117	Allnutt	846.333
118	Allnutt	846.0269
119	Allnutt	850.6226
120	Allnutt	859.745
121	Allnutt	849.869
122	Allnutt	852.5778
123	Allnutt	856.1723
124	Allnutt	842.0877
125	Allnutt	845.9733
126	Allnutt	851.8622
127	Allnutt	854.1089
128	Allnutt	858.2256
129	Allnutt	857.1241
130	Allnutt	847.315
131	Allnutt	851.5256
132	Allnutt	848.7002
133	Allnutt	850.7245
134	Allnutt	850.6215
135	Allnutt	846.9503
136	Allnutt	850.8151
137	Allnutt	858.1278
138	Allnutt	845.4063
139	Allnutt	861.7227
140	Allnutt	845.9679
141	Allnutt	851.1736
142	Allnutt	850.9553
143	Allnutt	859.8466
144	Allnutt	843.2371
145	Allnutt	852.9612
146	Allnutt	850.0685
147	Allnutt	846.5875
148	Allnutt	851.9555
149	Allnutt	851.5097
150	Allnutt	838.9322
151	Allnutt	849.7301
152	Allnutt	843.3559
153	Allnutt	850.2524
154	Allnutt	845.3382
155	Allnutt	852.4901
156	Allnutt	851.8635
157	Allnutt	846.6188
158	Allnutt	851.3145
159	Allnutt	848.3928
160	Allnutt	853.696
161	Allnutt	853.5458
162	Allnutt	849.0705
163	Allnutt	854.1199
164	Allnutt	851.8631
165	Allnutt	843.429
166	Allnutt	856.0384
167	Allnutt	852.4217
168	Allnutt	847.7065
169	Allnutt	843.5589
170	Allnutt	854.4876
171	Allnutt	856.0711
172	Allnutt	852.055
173	Allnutt	848.082
174	Allnutt	854.1909
175	Allnutt	853.7498
176	Allnutt	844.7622
177	Allnutt	842.3847
178	Allnutt	846.424
179	Allnutt	855.2979
180	Allnutt	851.0907
181	Allnutt	850.0135
182	Allnutt	854.4949
183	Allnutt	846.9333
184	Allnutt	844.2049
185	Allnutt	860.7341
186	Allnutt	850.3338
187	Allnutt	854.8068
188	Allnutt	848.2702
189	Allnutt	845.9338
190	Allnutt	854.6375
191	Allnutt	855.8982
192	Allnutt	846.4495
193	Allnutt	854.148
194	Allnutt	854.5809
195	Allnutt	848.2153
196	Allnutt	853.6106
197	Allnutt	846.7639
198	Allnutt	849.0568
199	Allnutt	851.1809
200	Allnutt	853.7476
201	Boltzmann	853.8771
202	Boltzmann	854.1824
203	Boltzmann	835.612
204	Boltzmann	853.0108
205	Boltzmann	853.1912
206	Boltzmann	854.6154
207	Boltzmann	853.6506
208	Boltzmann	855.6055
209	Boltzmann	854.7811
210	Boltzmann	855.6092
211	Boltzmann	865.3321
212	Boltzmann	856.5813
213	Boltzmann	850.8295
214	Boltzmann	856.485
215	Boltzmann	854.7527
216	Boltzmann	854.5054
217	Boltzmann	856.1014
218	Boltzmann	858.2229
219	Boltzmann	854.8437
220	Boltzmann	857.8417
221	Boltzmann	854.1254
222	Boltzmann	855.4286
223	Boltzmann	848.0421
224	Boltzmann	854.0324
225	Boltzmann	855.0561
226	Boltzmann	856.4439
227	Boltzmann	855.6163
228	Boltzmann	856.032
229	Boltzmann	853.9829
230	Boltzmann	857.7175
231	Boltzmann	850.2724
232	Boltzmann	857.9235
233	Boltzmann	855.3668
234	Boltzmann	854.1196
235	Boltzmann	855.345
236	Boltzmann	854.7549
237	Boltzmann	851.2849
238	Boltzmann	853.4281
239	Boltzmann	856.7178
240	Boltzmann	855.9313
241	Boltzmann	855.4032
242	Boltzmann	856.3888
243	Boltzmann	851.0976
244	Boltzmann	856.6964
245	Boltzmann	856.4571
246	Boltzmann	854.4644
247	Boltzmann	854.876
248	Boltzmann	855.7328
249	Boltzmann	854.9113
250	Boltzmann	852.8671
251	Boltzmann	853.7437
252	Boltzmann	854.4368
253	Boltzmann	856.2224
254	Boltzmann	850.9555
255	Boltzmann	855.6623
256	Boltzmann	854.3898
257	Boltzmann	854.3004
258	Boltzmann	853.9406
259	Boltzmann	855.1283
260	Boltzmann	855.6343
261	Boltzmann	854.9652
262	Boltzmann	852.8445
263	Boltzmann	854.5235
264	Boltzmann	851.3255
265	Boltzmann	855.1905
266	Boltzmann	853.198
267	Boltzmann	854.1671
268	Boltzmann	852.4987
269	Boltzmann	854.0756
270	Boltzmann	855.6302
271	Boltzmann	857.0688
272	Boltzmann	859.0456
273	Boltzmann	841.231
274	Boltzmann	854.0897
275	Boltzmann	853.1751
276	Boltzmann	829.1931
277	Boltzmann	849.4718
278	Boltzmann	855.7301
279	Boltzmann	854.2034
280	Boltzmann	847.8514
281	Boltzmann	854.5621
282	Boltzmann	848.1635
283	Boltzmann	855.2799
284	Boltzmann	854.6651
285	Boltzmann	855.1381
286	Boltzmann	854.0201
287	Boltzmann	851.3106
288	Boltzmann	855.3472
289	Boltzmann	854.8892
290	Boltzmann	851.2048
291	Boltzmann	854.7944
292	Boltzmann	854.5092
293	Boltzmann	852.4509
294	Boltzmann	857.484
295	Boltzmann	857.8509
296	Boltzmann	853.7584
297	Boltzmann	851.1856
298	Boltzmann	854.4417
299	Boltzmann	852.7422
300	Boltzmann	856.2729
301	Boltzmann	869.4711
302	Boltzmann	855.1584
303	Boltzmann	854.2219
304	Boltzmann	855.6442
305	Boltzmann	851.8485
306	Boltzmann	855.0067
307	Boltzmann	854.7371
308	Boltzmann	851.2858
309	Boltzmann	854.4992
310	Boltzmann	857.8474
311	Boltzmann	856.4243
312	Boltzmann	854.3994
313	Boltzmann	851.5604
314	Boltzmann	855.163
315	Boltzmann	852.9087
316	Boltzmann	854.7952
317	Boltzmann	854.926
318	Boltzmann	852.2318
319	Boltzmann	849.3958
320	Boltzmann	852.8113
321	Boltzmann	854.8909
322	Boltzmann	853.0809
323	Boltzmann	853.3958
324	Boltzmann	854.7141
325	Boltzmann	856.4498
326	Boltzmann	844.8167
327	Boltzmann	852.4545
328	Boltzmann	856.2205
329	Boltzmann	856.6331
330	Boltzmann	855.8913
331	Boltzmann	853.9867
332	Boltzmann	851.8579
333	Boltzmann	857.7252
334	Boltzmann	852.3514
335	Boltzmann	855.2167
336	Boltzmann	855.6327
337	Boltzmann	854.4452
338	Boltzmann	854.1149
339	Boltzmann	856.377
340	Boltzmann	854.513
341	Boltzmann	850.3847
342	Boltzmann	856.6687
343	Boltzmann	854.64
344	Boltzmann	866.5788
345	Boltzmann	854.9686
346	Boltzmann	853.9096
347	Boltzmann	852.5543
348	Boltzmann	855.485
349	Boltzmann	855.3543
350	Boltzmann	855.4542
351	Boltzmann	853.5034
352	Boltzmann	850.3386
353	Boltzmann	851.2501
354	Boltzmann	855.4448
355	Boltzmann	854.7506
356	Boltzmann	855.1525
357	Boltzmann	858.0726
358	Boltzmann	855.0837
359	Boltzmann	853.3975
360	Boltzmann	853.0623
361	Boltzmann	855.4873
362	Boltzmann	856.1406
363	Boltzmann	858.4089
364	Boltzmann	854.0833
365	Boltzmann	859.7965
366	Boltzmann	854.8329
367	Boltzmann	845.3066
368	Boltzmann	855.8432
369	Boltzmann	855.9198
370	Boltzmann	854.9996
371	Boltzmann	854.4814
372	Boltzmann	855.8368
373	Boltzmann	853.9241
374	Boltzmann	854.4554
375	Boltzmann	858.0965
376	Boltzmann	854.7574
377	Boltzmann	864.6641
378	Boltzmann	854.4772
379	Boltzmann	854.4473
380	Boltzmann	854.8034
381	Boltzmann	856.7892
382	Boltzmann	855.261
383	Boltzmann	854.3366
384	Boltzmann	854.6797
385	Boltzmann	859.6881
386	Boltzmann	855.7455
387	Boltzmann	855.199
388	Boltzmann	854.7199
389	Boltzmann	855.0506
390	Boltzmann	852.9435
391	Boltzmann	831.3796
392	Boltzmann	853.5944
393	Boltzmann	857.6592
394	Boltzmann	850.456
395	Boltzmann	852.1599
396	Boltzmann	854.2146
397	Boltzmann	853.7567
398	Boltzmann	855.621
399	Boltzmann	863.8533
400	Boltzmann	852.8602
401	Coachers	856.2687
402	Coachers	856.413
403	Coachers	856.4565
404	Coachers	855.9129
405	Coachers	856.0998
406	Coachers	856.3941
407	Coachers	856.7172
408	Coachers	856.3306
409	Coachers	856.3919
410	Coachers	856.3504
411	Coachers	856.3826
412	Coachers	856.4242
413	Coachers	856.5542
414	Coachers	856.5967
415	Coachers	856.4993
416	Coachers	856.4147
417	Coachers	857.978
418	Coachers	856.5473
419	Coachers	856.731
420	Coachers	856.1602
421	Coachers	856.4161
422	Coachers	856.3122
423	Coachers	856.3774
424	Coachers	856.4823
425	Coachers	856.5189
426	Coachers	856.545
427	Coachers	856.3595
428	Coachers	848.169
429	Coachers	856.3465
430	Coachers	856.3402
431	Coachers	856.5285
432	Coachers	856.4139
433	Coachers	856.4988
434	Coachers	856.6186
435	Coachers	814.3485
436	Coachers	857.1397
437	Coachers	856.3064
438	Coachers	856.5457
439	Coachers	856.6873
440	Coachers	856.4966
441	Coachers	856.5591
442	Coachers	856.4804
443	Coachers	856.0577
444	Coachers	856.4088
445	Coachers	857.2447
446	Coachers	856.45
447	Coachers	856.5919
448	Coachers	856.5812
449	Coachers	856.4228
450	Coachers	856.4427
451	Coachers	856.3566
452	Coachers	856.4102
453	Coachers	856.8596
454	Coachers	856.5385
455	Coachers	856.3751
456	Coachers	856.2154
457	Coachers	856.3129
458	Coachers	856.2692
459	Coachers	856.5972
460	Coachers	856.4091
461	Coachers	856.5448
462	Coachers	856.7963
463	Coachers	856.1371
464	Coachers	856.1713
465	Coachers	856.5833
466	Coachers	856.2324
467	Coachers	856.4971
468	Coachers	857.5763
469	Coachers	856.3857
470	Coachers	856.4832
471	Coachers	856.4907
472	Coachers	856.4261
473	Coachers	856.3389
474	Coachers	856.2792
475	Coachers	855.9439
476	Coachers	856.4362
477	Coachers	856.3606
478	Coachers	856.4685
479	Coachers	856.3011
480	Coachers	856.4856
481	Coachers	856.3257
482	Coachers	856.2612
483	Coachers	856.5538
484	Coachers	856.4977
485	Coachers	856.5463
486	Coachers	856.381
487	Coachers	856.4948
488	Coachers	856.5882
489	Coachers	856.5097
490	Coachers	856.4163
491	Coachers	855.9954
492	Coachers	856.3626
493	Coachers	856.454
494	Coachers	856.3616
495	Coachers	856.4227
496	Coachers	856.3931
497	Coachers	855.8224
498	Coachers	856.3919
499	Coachers	857.563
500	Coachers	856.4022
501	Coachers	856.3963
502	Coachers	856.5085
503	Coachers	856.2777
504	Coachers	856.3342
505	Coachers	856.3471
506	Coachers	856.5029
507	Coachers	856.4977
508	Coachers	856.4285
509	Coachers	856.3304
510	Coachers	856.4379
511	Coachers	856.3932
512	Coachers	856.3585
513	Coachers	856.0409
514	Coachers	857.0036
515	Coachers	856.562
516	Coachers	856.3949
517	Coachers	856.3549
518	Coachers	856.3625
519	Coachers	856.5949
520	Coachers	856.3763
521	Coachers	856.4577
522	Coachers	856.5202
523	Coachers	856.6245
524	Coachers	857.4004
525	Coachers	856.2774
526	Coachers	856.385
527	Coachers	856.4233
528	Coachers	856.4661
529	Coachers	856.7327
530	Coachers	854.7163
531	Coachers	856.2602
532	Coachers	856.5419
533	Coachers	856.4101
534	Coachers	856.4962
535	Coachers	856.4342
536	Coachers	856.6258
537	Coachers	856.4304
538	Coachers	856.2871
539	Coachers	856.692
540	Coachers	856.4315
541	Coachers	856.4791
542	Coachers	856.4952
543	Coachers	856.3599
544	Coachers	856.2455
545	Coachers	856.5158
546	Coachers	857.9868
547	Coachers	856.3007
548	Coachers	856.35
549	Coachers	856.3681
550	Coachers	856.0984
551	Coachers	855.6235
552	Coachers	856.6084
553	Coachers	856.5242
554	Coachers	856.373
555	Coachers	857.1091
556	Coachers	856.4931
557	Coachers	856.9949
558	Coachers	856.2052
559	Coachers	856.2559
560	Coachers	856.42
561	Coachers	856.0312
562	Coachers	856.6095
563	Coachers	856.4132
564	Coachers	856.4562
565	Coachers	856.5664
566	Coachers	856.0528
567	Coachers	856.7302
568	Coachers	856.3272
569	Coachers	857.7653
570	Coachers	856.4197
571	Coachers	856.4004
572	Coachers	856.2744
573	Coachers	857.5671
574	Coachers	856.3951
575	Coachers	856.3316
576	Coachers	861.627
577	Coachers	856.3888
578	Coachers	856.3602
579	Coachers	852.262
580	Coachers	856.3461
581	Coachers	856.553
582	Coachers	856.0203
583	Coachers	856.5269
584	Coachers	856.46
585	Coachers	856.3876
586	Coachers	856.4328
587	Coachers	856.541
588	Coachers	856.2757
589	Coachers	852.2726
590	Coachers	856.4479
591	Coachers	856.5216
592	Coachers	856.4499
593	Coachers	856.5147
594	Coachers	856.4065
595	Coachers	857.0023
596	Coachers	856.5846
597	Coachers	856.4244
598	Coachers	856.6109
599	Coachers	856.5324
600	Coachers	856.4484

Answer 1

By observing the box plot and the descriptive statistics,we can say that the supplier Allnutt is uniformly distributed.If we see the box plot of 3 suppliers,in second and third case there are many outliers present.The third supplier is most consistent but the value of mean ,first quartile median and third quartile is same. But by our problem Coachers have highest tensile strength and consistent according to me should be recomandable though it is not uniformly placed.