The I.Q.’s of 10 teenagers belonging to one ethnic group are 98, 114, 105, 101, 123, 117, 106, 92, 110, and 108, whereas those of 6 teenagers belonging to another ethnic group are 122, 105, 99, 126, 114, and 108. Assuming that these data can be looked upon as independent random samples from normal populations with the means µ₁ and µ₂ and the common variance σ², estimate these parameters by means of the maximum likelihood estimators obtained in Exercise 10.71.