Question

For 126 consecutive days, a process engineer has measured the temperature of champagne bottles as they are made ready for serving. Each day, she took a sample of 8 bottles. The average across all 1,008 bottles (126 days, 8 bottles per day) was 58 degrees Fahrenheit. The standard deviation across all bottles was 1.5 degree.

When constructing an X-bar chart, what would be the center line?

Answer 1

58 degrees fahrenheit

Step-by-step explanation:

the centerline will be 58 degrees fahrenheit

the upper control limit = 58 degrees + (1.099 x 1.5) = 59.6485 degrees fahrenheit

the lower control limit = 58 degrees - (1.099 x 1.5) = 56.3515 degrees fahrenheit

the A₃ control value for n = 8 is 1.099