A researcher wished to test the effect of the addition of extra calcium to yogurt on the tastiness of yogurt. A collection of 200 adult volunteers was randomly divided into two groups of 100 subjects each. Group 1 tasted yogurt containing the extra calcium. Group 2 tasted yogurt from the same batch as group 1 but without the added calcium. Both groups rated the flavor on a scale of 1 to 10, with 1 being very unpleasant and 10 being very pleasant. The mean rating for group 1 was X 1 = 6.5 with a standard deviation of s1 = 1.5. The mean rating for group 2 was X 2 = 7.0 with a standard deviation of s2 = 2.0. Assume the two groups ratings are independent. Let μ1 and μ2 represent the mean ratings we would observe for the entire population represented by the volunteers if all members of this population tasted, respectively, the yogurt with and without the added calcium.