Last year, your company's service technicians took an average of 2.6 hours to respond to trouble calls from business customers who had purchased service contracts. Your company wants to find out if this year's data show a different average response time. In order to do so, they review 42 service calls and construct a 95% confidence interval for population mean: (2.468, 2.743).
What can we conclude about the significance test of Ho: mu = 2.6 vs Ha: mu does not equal 2.6 ?