Creatine kinase (CK) is found predominantly in muscle and is released into the cir- culation during muscular lesions. Therefore, serum CK activity has been theoretically expected to be useful as a marker in exercise physiology and sports medicine for the detection of muscle injury and overwork. The following data represent the peak CK activity (measured in IU/L) after 90 minutes of exercise in 15 healthy young men. (Source: Manabu Totsuka, Shigeyuki Nakaji, Katsuhiko Suzuki, Kazuo Sugawara, and Koki Sato, Break point of serum creatine kinase release after endurance exercise, https://jap.physiology.org/cgi/content/full/93/4/1280.)
1112 722 689 251 196 185 128 102 166 178
775 694 514 244 208
Construct a 95% con?dence interval for the mean peak CK activity.