allie : (6.5 + 9) / 2 = 15.5/2 = 7.75 (mean of allie)
franco : (6 + 10.5)/2 = 16.5/2 = 8.25 (mean for franco)
blake : (8 + 7)/2 = 15/2 = 7.5 (mean for blake)
to find the mean, u would add up the number of hrs on those 2 days, then divide by 2.
Blake's mean would be : (4b + 4c) / 2 = 4d
