Final answer:
The provided information does not directly answer the question about network utilization.
Step-by-step explanation:
The question is asking about the percentage of network utilization that can be expected to perform well. However, the provided information does not directly give this percentage. It provides information about mean excess time used by customers who exceed their contracted time allowance in a sample of 80 customers.
It also provides information about the 95th percentile for the sample mean excess time used and a confidence interval for the percentage of adult residents with cell phones. None of these directly answer the question about network utilization.