The scatter plot 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.

Response variable is Men-Women
R-squared = 51.9%
s = 0.2143 with 37 - 2 = 35 degrees of freedom

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.