Which one of these diagrams shows how process capability can be determined?

The choice indicating Diagram C is likely correct because it typically illustrates the key elements required to assess process capability effectively. A process capability diagram usually includes components such as the distribution of process data, specification limits, and capability indices like Cp, Cpk, Pp, and Ppk. These elements together provide a visual representation of how well a process can meet specified limits and the extent of variation within the process.

The main focus of a process capability analysis is to compare the inherent variability of a process against the specifications set forth. Diagram C likely illustrates this relationship, showcasing the data points, such as the mean and the standard deviation, in relation to the upper and lower specification limits. This visual representation enables a quick understanding of whether the process is capable of producing items within the specified limits.

In contrast, the other diagrams (A and B) may not clearly depict the necessary elements to understand process capability. They might focus on unrelated aspects of process flow or data representation that do not provide the specific insights needed to evaluate process capability properly. Thus, the understanding that Diagram C encompasses the critical features for determining process capability makes it the accurate choice.