A farmer decides to test the effect of a new feeding regime on his chickens. For the chickens fed on the original regime, the mean weight of 100 eggs is 57.2 g with a standard deviation of 2.1 g. For chickens fed on the new regime, the mean weight of 100 eggs is 57.7 g with a standard deviation of 2.3 g. What is the probability that there could be that difference or more in the means of the two samples if the new feeding regime was ineffective?