Final answer:
The range between desired and adequate services can vary from narrow to wide based on customer expectations. It can be theoretically fixed by standards, but variations are common in practice. Understanding these ranges is crucial for service delivery and customer satisfaction.
Step-by-step explanation:
The range of expectations between desired and adequate services can be narrow, be wide, or be perceived differently depending on individual customer expectations and experiences. In theory, it can also be fixed if standardized expectations are set by a given industry or service provider, although, in practice, variations usually exist. The answer does not include 'cannot be determined' because it is typically possible to determine and analyze customer expectations through market research and feedback mechanisms.