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

Clearly, the patterns for men and women are similar. But are the two lines getting closer together?
Here's 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.

Dependent variable is Age Difference
R-squared = 74.9%s = 0.2346
Variable                                            Coefficient
Intercept .................................           32.968
Year ..........................................       -0.01549
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.

Transcribed Image Text:

30 28 eh Men Women 26 24 20+ 1900 1920 1940 1960 1980 2000 2020 Year 4.0 3.5 3.0 2.5 2.0 1.5 1900 1920 1940 1960 1980 2000 2020 Year 0.2 0.0 0.2 -0.4 1900 1920 1940 1960 1980 2000 Year