For 132 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 5 bottles. The average across all 660 bottles (132 days, 5 bottles per day) was 51 degrees Fahrenheit. The standard deviation across all bottles was 1.4 degrees Fahrenheit.
When constructing an X-bar chart, what would be the center line? degrees Fahrenheit