Use the one-proportion plusfour z-interval procedure, as discussed on page $551,$ to find the required confidence interval. Interpret your results.
In the May 2008 New York Times article "More Mothers Breast-Feed, in First Months at Least,"
G. Harris reported that $77 \%$ of new mothers breast-feed their infants at least briefly, the highest rate seen in the United States in more than a decade. His report was based on data for 434 infants from the National Health and Nutrition Examination Survey, which involved in-person interviews and physical examinations. Find a $90 \%$ confidence interval for the percentage of all new mothers who breast-feed their infants at least briefly.