In its first year of operations, Roma Company reports the following:
1 answer:
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Answer:
Control limits for x_bar are between 59.076 and 60.924
Control limits for R are between 0.669 and 5.331
Explanation:
Given data:
x_bar = 60 mph
n = 10
R = 3 mph
Step 1: Factors (see table attached)
At n = 10, factors for computing control charts limits are,
A2 = Mean factor = 0.308
D3 = Lower range = 0.223
D4 = Upper range = 1.777
Step 2: Control limits for x_bar
Lower Control limit:
LCL = x_bar - A2*R = 60 - (0.308)(3) = 60 - 0.924 = 59.076
Upper Control limit:
UCL = x-bar + A2*R = 60 + (0.308)(3) = 60 + 0.924 = 60.924
The control limits for x_bar are between 59.076 and 60.924
Step 3: Control limits for R
Lower Control limit:
LCL = D3*R = 0.223(3) = 0.669
Upper Control limit:
UCL = D4*R = 1.777(3) = 5.331
The control limits for R are between 0.669 and 5.331
Hope this helps!
