15 A study using a probability sample from the 1984 National Health Interview Study (R. Coward et al., The Gerontologist. Vol. 35, 1995. pp. 24-34) reported that the percent of respondents with income below the poverty level was 11.3% for residents of metropolitan areas (n=7331) and 20.6% for residents of nonmetropolitan areas (n=4235) Construct and interpret a 99% confidence interval for the difference in poverty rates between non- metropolitan and metropolitan areas What is the effect of the very large sample sizes on the interval?