The World Health Organization commissioned a study with the University of Florida to understand the gender differences in exercise habits between men and women. UF researchers collected summary exercise information from a random sample of 108 women (group 1) and 72 men (group 2) in Alachua county. Women's energy expenditure over a week span (average of 143.8 calories/min with an SD = 123.1 calories/min) was higher than men's energy expenditure over the same week (average of 111.5 calories/min with an SD = 120.2 calories/min). The researchers believe that women tend to exercise more than men. The correct null and alternative hypotheses to test this proposition are