Table 16-1
-Refer to Table 16-1. To guarantee that cans of soup are properly filled, some cans are sampled and the amounts measured. The overall average for the samples is 12 ounces. Each sample contains 10 cans. The average range is 0.4 ounces. The upper control chart limit for the sample averages would be
A) 12.1232.
B) 11.8768.
C) 13.2.
D) 12.308.
E) None of the above

Question

Table 16-1 
-Refer to Table 16-1. To guarantee that cans of soup are properly filled, some cans are sampled and the amounts measured. The overall average for the samples is 12 ounces. Each sample contains 10 cans. The average range is 0.4 ounces. The upper control chart limit for the sample averages would be
A) 12.1232. 
B) 11.8768. 
C) 13.2. 
D) 12.308. 
E) None of the above

Quizplus · Accepted Answer

Since the sample size is 10, we need to use the factors for the X̄ and R chart with sample size 10. From Table 16-3, the factor for X̄ chart is 0.577 and for R chart is 2.282.

Upper Control Limit for X̄ chart = X̄ + A2R
where A2 is the factor for the X̄ chart and R is the average range.

Upper Control Limit for X̄ chart = 12 + (0.577)(0.4) = 12.2312

Therefore, the upper control chart limit for the sample averages would be 12.1232 (12.2312 - 0.108) which is choice A.

Table 16-1 -Refer to Table 16-1. to Guarantee That Cans of Soup