Has the trend of de-creasing difference in age at first marriage seen in Exercise gotten stronger recently? Here are the scatterplot and residual plot for the data from 1975 through 2011, along with a regression for just those years.

Dependent variable is: Men €“ Women
R- squared = 51.9% s = 0.2143
Variable Coeff
Intercept 42.5662
Year - 0.0203
a) Why is R2 higher for the first model (in Exercise 40)?
b) Is this linear model appropriate for the post- 1975 data? Explain.
c) What does the slope say about marriage ages since 1975?
d) Explain why it€™s not safe to interpret the y- intercept.

Transcribed Image Text:

275 2.50 2.25 2.00 1.75 1980 190 2000 2010 feor 04 00 . 195 210 225 240 Predicted (M-W