Learning a foreign language
Does delaying oral practice hinder learning a foreign language? Researchers randomly assigned 25 beginning students of Russian to begin speaking practice immediately and another 25 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(32, 6) distribution and scores for delayed speaking have the N(29, 5) distribution.
(a) What is the sampling distribution of the mean score x in the early-speaking group in many repetitions of the experiment? What is the sampling
(b) The survey wants to compare men and women. What is the approximate distribution of the difference in the proportions who worked, pˆ M - pˆ F ? Explain the reasoning behind your answer.
(c) What is the probability that in the sample a higher proportion of women than men worked last summer?