"Age at First Marriage The following time-series plot shows the average age at which individuals first marry by gender for each year of the census since 1890.
a. To the nearest year, what was the average age of a man who first married in 1980?"

Verified step by step guidance

1. Identify the year of interest on the horizontal axis, which is 1980 in this case.
2. Locate the blue line on the graph, as it represents the average age at first marriage for men.
3. Find the point on the blue line that corresponds to the year 1980.
4. Trace horizontally from this point to the vertical axis to determine the average age value.
5. Round the value to the nearest whole number to find the average age of a man who first married in 1980.

Key Concepts

Time-Series Data

Time-series data consists of observations collected sequentially over time. In this question, the average age at first marriage is recorded for each census year, allowing us to analyze trends and changes over decades.

Reading Graphs and Interpreting Data Points

To answer the question, one must accurately read the graph by locating the year 1980 on the x-axis and then identifying the corresponding data point for men. This skill involves understanding axes, legends, and how to estimate values from plotted points.

Comparative Analysis by Categories

The graph compares two categories—men and women—over time. Understanding how to distinguish and interpret multiple data series on the same graph is essential for analyzing differences and trends between groups.