A nurse anesthetist was experimenting with the use of nitronox as an anesthetic in the treatment of children's fractures of the arm. She treated 50 children and found that the mean treatment time (in minutes) was 26.26 minutes with a sample standard deviation of 7.13 minutes. She wanted to build a 95% confidence interval for the true mean treatment time. What would that be n=50; mean 26.26 minutes, SD 7.13, she wanted to buid a CI of 95% for the true mean of treatment time.