An economics professor is interested in finding the mean hours worked by ISU students in a week at part time or full time jobs (including work study). The professor obtains a new sample and the 99% confidence interval for the mean hours worked by ISU students is from 5 to 10 hours worked per week. Please interpret this confidence interval. We are certain the true mean number of hours worked by ISU students in a week is between 5 and 10 hours. We are 99% confident the true mean number of hours worked by ISU students in a week is between 5 and 10 hours. With probability 99%, the true mean number of hours worked by ISU a week is between 5 and 10. The true mean number of hours worked by ISU students is 7.5 hours per week