Question

For 115 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 10 bottles. The average across all 1,150 bottles (115 days, 10 bottles per day) was 40 degrees Fahrenheit. The standard deviation across all bottles was 0.5 degree Fahrenheit.
Required:
When constructing an X-bar chart, what would be the center line?

Answer 1

Answer:

40° Fahrenheit

Explanation:

For an X-bar, the centre line is then average across all components. In this case, the average temperature across all 1150 bottles over 115 days will be 40° Fahrenheit as it is reported.