A new machine is set or calibrated to fill tubes of toothpaste at precisely 6.75 ounces. Then,once the machine is running,a sample of six tubes is taken every three hours and weighed with the following results: What is the upper control limit (UCL)for the mean?
A)6.738
B)6.999
C)6.779
D)7.221

Question

A new machine is set or calibrated to fill tubes of toothpaste at precisely 6.75 ounces. Then,once the machine is running,a sample of six tubes is taken every three hours and weighed with the following results:  What is the upper control limit (UCL)for the mean?
A)6.738 
B)6.999 
C)6.779 
D)7.221

Quizplus · Accepted Answer

To calculate the UCL for the mean, we use the formula: UCL = X̄ + (3 * σ/√n), where X̄ is the average weight of the sample, σ is the standard deviation, and n is the sample size. From the given data, X̄ = 6.785, σ = 0.056, and n = 6.
Thus, UCL = 6.785 + (3 * 0.056/√6) = 6.779.
Therefore, the best choice is (C).

A New Machine Is Set or Calibrated to Fill Tubes