4 An internet service provider sampled 540 customers and fou

4. An internet service provider sampled 540 customers and found that 75 of them experienced an interruption in high-speed service during the previous month.

a) Calculate a 95% confidence interval for the proportion of all customers who experienced an interruption.

b) The company’s quality control manager claims that no more than 10% of its customers experienced an interruption during the previous month. Does the confidence interval contradict this claim? Explain.

Solution