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Marriage age 2011 again Has the trend of decreasing
Chapter 8, Problem 38E(choose chapter or problem)
Marriage age 2011 again Has the trend of decreasing difference in age at first marriage seen in Exercise 36 gotten stronger recently? The scatterplot and residual plot for the data from 1980 through 2011, along with a regression for just those years, are below.
a) Is this linear model appropriate for the post-1980 data? Explain.
b) What does the slope say about marriage ages?
c) Explain why it’s not reasonable to interpret the y-intercept.
Questions & Answers
QUESTION:
Marriage age 2011 again Has the trend of decreasing difference in age at first marriage seen in Exercise 36 gotten stronger recently? The scatterplot and residual plot for the data from 1980 through 2011, along with a regression for just those years, are below.
a) Is this linear model appropriate for the post-1980 data? Explain.
b) What does the slope say about marriage ages?
c) Explain why it’s not reasonable to interpret the y-intercept.
ANSWER:Step 1 of 3
(a) Linearity: Not violated, because there is no strong curvature present in the scatterplot nor in the residual plot
Outliers: Not violated, because there are no points that strongly deviate from the pattern in the other points.
Equal variances: Not violated, because the vertical spread in the points is roughly the same everywhere in the residual plot.
Since none of the assumptions are violated, the linear model is appropriate for the post-1980 data.