a A triathlon consisting of swimming cycling and running is

a) A triathlon consisting of swimming, cycling, and running is one of the more strenuous amateur sporting events. An article reports on a research study involving sixteen male triathletes. Maximum heart rate (beats/min) was recorded during performance of each of the three events. For swimming, the sample mean and sample standard deviation were 187.0 and 7.1, respectively. Assuming that the heart-rate distribution is (approximately) normal, construct a 98% CI for true mean heart rate of triathletes while swimming. (Round your answers to one decimal place.)

b) It is important that face masks used by firefighters be able to withstand high temperatures because firefighters commonly work in temperatures of 200-500

Solution

9 athletes

mean = 187.0

sd = 7.1

ta/2 = invt(.98,df=8) = 2.8965

187.0 +/- 2.8965*7.4/square root of 9

187.0 +/- 7.1446

lower: 179.855

Upper: 194.14