Question: Marriage and divorce statistics are compiled by the National Center for Health Statistics and published in volumes of Vital Statistics of the United States. State and local officials provide NCHS with annual counts of marriages and divorces in each county. In addition, some states send computer tapes of additional data or microfilm copies of marriage or divorce certificates. These additional data are used to calculate statistics about age at marriage or divorce, previous marital status of marrying couples, and children involved in divorce. In 1987, if a state sent a computer tape, all records were included in the divorce statistics; if a state sent microfilm copies, a specified fraction of the divorce certificates was randomly sampled and data recorded. The sampling rates (probabilities of selection) and number of records sampled in each state in the divorce registration area for 1987 are in the file divorce.dat.
a How many divorces were there in the divorce registration area in 1987? HINT: Use the sampling weights.
b Why did NCHS use different sampling rates in different states?
c Estimate the total number of divorces granted to men aged 24 or less; to women aged 24 or less. Give 95% CIs for your estimates.
d In what proportion of all divorces is the husband between 40 and 49 years old? In what proportion is the wife between 40 and 49 years old? Give confidence intervals for your estimates.