Question 10.203

9. The Centers for Disease Control, in their Pregnancy Risk Assessment Monitoring System, reported that 641 of 823 new mothers living in Florida and 658 of 824 new mothers living in North Carolina took their babies in for a checkup within one week of delivery.22

  1. Find a 99% confidence interval for the difference in population proportions.
  2. Perform a hypothesis test of whether the population proportions differ, at level of significance , using the -value method.

10.99.9

(a) (–0.0715, 0.0322) (b) Since the is not ≤ 0.01, we do not reject . There is insufficient evidence that the population proportion of new mothers in Florida who took their babies in for a checkup within one week of delivery is different from the proportion of new mothers in North Carolina who took their babies in for a checkup within one week of delivery.