Final answer:
Mean (X-bar) and range (R-) charts are used together in statistical process control to monitor and analyze the variation in a process. The mean chart shows the average value of a quality characteristic over time, while the range chart shows the variability or spread of the data. By using both charts together, we can detect if the process is in control or out of control.
Step-by-step explanation:
Mean (X-bar) and range (R-) charts are used together in statistical process control to monitor and analyze the variation in a process. The mean chart shows the average value of a quality characteristic over time, while the range chart shows the variability or spread of the data.
By using both charts together, we can detect if the process is in control (i.e., variation is within acceptable limits) or out of control (i.e., variation exceeds acceptable limits). If both charts indicate that the process is in control, we can be confident that the process is producing consistent and acceptable results.
For example, let's say we are monitoring the weight of chocolate bars produced by a machine. The mean chart will show if the average weight is stable over time, while the range chart will show if there are any unexpected variations in weight. If the mean and range charts indicate that the process is in control, we can be confident that the machine is producing chocolate bars within the desired weight range.