A producer of specialty products uses a variety of natural and man-made materials to make unique countertops for kitchens and baths.One product line mixes concrete and natural river stone to make countertops that are polished to a high shine revealing unique patterns.Occasionally coarse sand will result in undesirable pitting and rough spots on surfaces.Consequently, as part of its quality control efforts, 8 by 4 foot polished slabs are checked periodically for imperfections.For each slab inspected the number of imperfections (pits, rough spots, etc.) is recorded.If the average number of imperfections per 8 by 4 foot polished slab is 2.6, the control limits for the appropriate control chart are ________________________ .
A)0 and 7.44
B)0.98 and 4.21
C)0 and 9.89
D)1.24 and 3.96
E)None of the above.

Question

Quizplus · Accepted Answer

The control limits for the appropriate control chart can be calculated using the formula for the control limits of a Poisson distribution, which is appropriate for count data like the number of imperfections. The formula is LCL = μ - 3√μ and UCL = μ + 3√μ, where μ is the average number of imperfections (2.6 in this case). Calculating the limits gives us 0 and 7.44, as negative values are not possible for counts, making the lower control limit 0.

A Producer of Specialty Products Uses a Variety of Natural