Sarah Soliz, Director of Quality Programs, is designing and R charts for the rod shearing process at Stockton Steel.She has 26 samples of rod length, and each sample included measurements of 5 rods.The mean of the 26 sample means is 112 centimetres, and mean of the 26 ranges is 0.15 centimetres.The centerline for her chart is ___.
A)5
B)26
C)0.15
D)11.2
E)112

Question

Sarah Soliz, Director of Quality Programs, is designing  and R charts for the rod shearing process at Stockton Steel.She has 26 samples of rod length, and each sample included measurements of 5 rods.The mean of the 26 sample means is 112 centimetres, and mean of the 26 ranges is 0.15 centimetres.The centerline for her  chart is ___.
A)5 
B)26 
C)0.15 
D)11.2 
E)112

Quizplus · Accepted Answer

For the X-bar chart, the centerline is calculated as the average of all sample means, which is given as 112 centimetres.
Therefore, the centerline for the X-bar chart is 112 centimetres.

Sarah Soliz, Director of Quality Programs, Is Designing and R