Final answer:
For sample 2, you should plot the mean of the given numbers, which is 8.128, rounded to 8.130, on the x-bar chart.
Step-by-step explanation:
The question asks what would be plotted on an x-bar chart for sample 2. In the context of statistical process control, an x-bar chart is a type of control chart used to monitor the mean values of a sample over time. For sample 2, you would plot the mean (average) of the provided numbers. In this case, after adding the numbers 8.34, 8.22, 7.77, 8.18, and 8.13 and dividing by the number of observations, which is 5, the mean is 8.128. So, you would plot point 4) Only 8.130 (rounded to three decimal places) on the x-bar chart for sample 2.