An Internet service provider sampled 558 customers and found that 90 of them experienced an interruption in service during the previous month. a. Construct a 86% confidence interval for the proportion of all customers who experienced an interruption. Critical value: z * or t * = Enter the positive one.) Margin of Error: E = Confidence Interval: b. Interpret your result in part (a) in a complete sentence. c. Based on the confidence interval, can you conclude that less