Ages of couples 2003. The graph shows the ages of both men and women at first marriage. (www.census. gov)
Clearly, the pattern for men is similar to the pattern for women. But are the two lines getting closer together?
Here's a time plot showing the difference in average age (men's age - women s age) at first marriage, the regression analysis, and the associated residuals plot.
a) What is the correlation between Age Difference and Year?
b) Interpret the slope of this line.
c) Predict the average age difference in 2015.
d) Describe reasons why you might not place much faith in that prediction.