=+40. Age at first marriage 2011, part 2. In Exercise 21 we looked at the age at which women married as one of the variables considered by those selling wedding services. Another variable of concern is the difference in age of the two partners.

The graph shows the ages of both men and women at first marriage. (www.census.gov) Age at First Marriage (years)

1890 1910 1930 1950 1970 1990 2010 Year 25 23 21 27 29 Clearly, the pattern for men is similar to the pattern for women. But are the two lines getting closer together?

Here is a timeplot showing the difference in average age (men’s age – women’s age) at first marriage, the regression analysis, and the associated residuals plot.

3.85 2.35 3.10 1.60 Men’s Age – Women’s Age (years)

1880 1940 1970 2000 Year 1910 Residuals 2.0 2.5 3.0 3.5 Predicted (M–W)

−0.2 0.4 0.2 0.0 Dependent variable is: Age Difference R-squared = 74.9% s = 0.2346 Variable Coeff Constant 32.9679 Year -0.01549