Does delaying oral practice hinder learning a foreign language? Researchers randomly assigned 15 beginning students of Russian to begin speaking practice immediately and another 15 to delay speaking for 4 weeks. At the end of the semester both groups took a standard test of comprehension of spoken Russian. Suppose that in the population of all beginning students, the test scores for early speaking vary according to the N(31, 9) distribution and scores for delayed speaking have the N(23, 8) distribution.