A critical dimension of the service quality of a call center is the wait time for a caller to get to a customer service

[answerhappygod]

A critical dimension of the service quality of a call center is
the wait time for a caller to get to a customer service
representative. Periodically, random samples of three customer
calls are measured with respect to these wait times. The results of
the last four such samples are provided in the accompanying Excel
file.
Suppose that the process has been determined to be within
statistical control. If the specifications for wait time are 500 ±
21 seconds, is the process capable of meeting the specifications?
Justify your answer. Assume that three-sigma performance is
desired; thus, the target capability measure is 1.0.