Marriage age 2011 The scatterplot suggests a decrease in the difference in ages at first marriage for men and women since 1975. We want to examine the regression to see if this decrease is significant.

a) Write appropriate hypotheses.

b) Here is the residuals plot and a histogram of the residuals.
Do you think the conditions for inference are satisfied? Explain.

c) Test the hypothesis and state your conclusion about the trend in age at first marriage.

2.50- 2.25- 2.00+ Men-Women 1.75- 1980 1990 2000 2010 Year