Table 15-1

-Refer to Table 15-1.To guarantee that cans of soda 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 lower control chart limit for the sample averages would be
A)12.1232.
B)11.8768.
C)13.2.
D)12.308.

Question

Table 15-1
 
-Refer to Table 15-1.To guarantee that cans of soda 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 lower control chart limit for the sample averages would be
A)12.1232. 
B)11.8768. 
C)13.2. 
D)12.308.

Quizplus · Accepted Answer

The lower control chart limit for the sample averages can be calculated using the formula:
Lower Control Limit = Overall Average - (A2 x Average Range)
where A2 is a constant based on the sample size (in this case, 10 cans per sample).
From the given information, the overall average is 12 ounces and the average range is 0.4 ounces. 
The value of A2 can be found from a table of control chart constants and is 0.577 for a sample size of 10. 
Substituting these values into the formula:
Lower Control Limit = 12 - (0.577 x 0.4) = 11.8768
Therefore, the lower control chart limit for the sample averages would be 11.8768 ounces, which corresponds to choice B.

Table 15-1 -Refer to Table 15-1.To Guarantee That Cans of Soda Are