In a study, a random sample of 34 male college students ran one mile while another random sample of 38 male college students walked the same mile. On average, those who ran burned 112 calories while those who walked burned 89 calories. Determine the degrees of freedom for a hypothesis test for the difference between the two population means for population variances assumed unequal (nonpooled estimate of the standard deviation) to test whether running burns more calories than walking?