ACME Internet Services offers residential broadband services and guarantees compensation for service delays if service calls cannot be resolved within an hour. Determine the narrowest time range that encompasses 50% of all service calls handled by ACME Internet Services (Assume that service call durations follow a normal distribution with an average of 53 minutes and a standard deviation of 9 minutes). a. 15.67 b. 18.96 c. 17.65 d. 16.19 e. 12.14 f. 14.33