A triathlon consisting of swimming, cycling, and running is one of the more strenuous amateur
sporting events. The article "Cardiovascular and Thermal Response of Triathlon Performance"
(Medicine and Science in Sports and Exercise, 1988: 385 ) reports on a research study
involving nine male triathletes. Maximum heart rate (beats/min) was recorded during perfor-
mance of each of the three events. For swimming, the sample mean and sample standard
deviation were 188.0 and $7.2,$ respectively. Assuming that the heart-rate distribution is (approx-
imately) normal, construct a 98$\%$ CI for true mean heart rate of triathletes while swimming.