The following data has been collected on the interarrival times of patients to an emergency department: 3.772, 1.761, 0.743, 15.988, 0.412, 7.541, 6.900, 3.447, 7.024, 1.061, 5.449, 0.309, 0.766, 4.807, 8.143, 0.093, 9.524, 0.012, 4.634, and 0.195 minutes.

Estimate the squared coefficient of variation of the arrival process. Is the arrival process likely to be Poisson? Why or why not? Estimate the arrival rate?