PRACTICE EXERCISES FOR WYETH MINITAB SEMINARacademic.uprm.edu/dgonzalez/adiestramientos/Manual _ de ejercicio… · PRACTICE EXERCISES FOR WYETH MINITAB SEMINAR David R. González

PRACTICE EXERCISES FOR WYETH MINITAB SEMINAR

David R. González Barreto Wyeth, Carolina Puerto Rico Adiestramiento de Minitab P a g e | 1

1. The following table shows the measurements of the length of a manufactured

plastic part before and after been submitted to a thermal process.

Part Before Thermal P. After Thermal P. Difference 1 10.49 9.11 1.38 2 16.62 13.25 3.37 3 17.30 14.72 2.58 4 15.48 12.74 2.74 5 12.97 10.12 2.85 6 17.26 14.57 2.69 7 13.40 11.22 2.18 8 13.90 11.10 2.8 9 13.63 11.42 2.21 10 13.26 10.91 2.35 11 14.37 12.11 2.26 12 11.70 8.62 3.08 13 15.47 12.59 2.88 14 17.84 15.09 2.75 15 14.07 10.55 3.52

- Construct a boxplot for both treatments (before and after). Discuss the plots. - Is the thermal process affecting the mean length of the plastic part? - What change in the part length could be detected by this test if we use a

confidence level of 95% and a power of 90%? Would you increase your sample size?







Prueba Pareada



Análisis de Tamaño de Muestra







2. In a study performed, Machine A produces 56 of 200 parts with non-acceptable

aesthetics characteristics, Machine B produced 29 of 150 parts that were rejectable due to the same characteristics. - Can we conclude that there is significant difference in the rejection rate of the

two machines?





3. The pH of a solution is an important characteristic of a process being studied. There is a claim that the average pH produced in the solution is 6.5. Nine prepared solution were observed rendering the following results: 7.3, 6.5, 6.4, 6.1, 6.0, 6.5, 6.2, 5.8, 6.7.

- Do these readings cast doubt upon the claimed average.







4. Is the normal probabilistic model reasonable for the following 20 observations? If,

so, estimate the probability of having a random observation between 20 and 28.

27.29 24.78 24.01 24.26 27.51 25.72 24.51 26.51 27.07 23.41

25.76 26.43 20.84 22.65 27.93 24.16 24.57 22.85 21.66 24.21









5. Four laboratories are being used to perform chemical analyses. Samples of the

same material are sent to the laboratories for analysis as part of the study to determine whether or not the give on the average the same results. The analytical results for the four laboratories are as follows:

Laboratory A B C D

58.7 62.7 55.9 60.7 61.4 64.5 56.1 60.3 60.9 63.1 57.3 60.9 59.1 59.2 55.2 61.4 58.2 60.3 58.1 62.3







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PRACTICE EXERCISES FOR WYETH MINITAB SEMINARacademic.uprm.edu/dgonzalez/adiestramientos/Manual _ de ejercicio… · PRACTICE EXERCISES FOR WYETH MINITAB SEMINAR David R. González