IV.13. When shall we call you? Suppose that we know that 57% of all calls made by sample surveys on weekday mornings are answered. We make 2454 calls to randomly chosen numbers during weekday evenings. Of these, 1840 are answered. Is this good evidence that the proportion of answered calls is higher in the evening?

  1. (a) State the hypotheses to be tested. (Hint: See pages 522–525.)

  2. (b) If your null hypothesis is true, what is the sampling distribution of the sample proportion ? Sketch this distribution. (Hint: See pages 522–528.)

  3. (c) Mark the actual value of on the curve. In your opinion, does it appear surprising enough to give good evidence against the null hypothesis? (Hint: See pages 522–528.)