Question

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Explanation:

Read values for 2020

Using the Stacked Line Chart Interpretation knowledge point

• The bottom region represents "Male" (light blue) and the top region represents "Female" (dark grey).
• In the year 2020, the boundary line between the Male and Female regions is at \(1.0\) million (which is \(1,000,000\)). This represents the number of degrees awarded to males.
• The top boundary of the stacked chart in 2020 is at \(2.1\) million (which is \(2,100,000\)).
• The number of degrees awarded to females is the difference:

$$ 2,100,000 - 1,000,000 = 1,100,000 $$

Determine when values were equal

Using the Stacked Line Chart Interpretation knowledge point

• The two groups are equal when the height of the Male region equals the height of the Female region.
• This means the boundary line between them must be exactly halfway to the top line of the chart (i.e., the Male region is half of the total height).
• Looking at the chart, from 1970 to around 1980, the Male region is thicker than the Female region.
• Around 1980, the boundary line is at approximately \(0.5\) million, and the total height is approximately \(1.0\) million. Thus, both males and females received about \(500,000\) degrees.
• Therefore, the numbers were approximately equal in 1980.

Identify the decade of greatest increase

Using the Stacked Line Chart Interpretation knowledge point

• We look for the decade where the total height (the top line of the stacked chart) has the steepest upward slope.
• From 1970 to 2000, the top line is relatively flat or rising very gradually.
• From 2000 to 2010, the top line rises more noticeably.
• From 2010 to 2020, the top line rises very sharply (from around \(1.4\) million to \(2.1\) million, an increase of about \(700,000\)).
• Therefore, the total number of degrees increased the most during the decade 2010–2020.

Evaluate the visualization effectiveness

Using the Data Visualization Evaluation knowledge point

• Stacked line charts are excellent for showing the changing total sum over time.
• However, because the female layer is stacked on top of the male layer, it does not start from a flat baseline, making it difficult to compare the exact values or trends of the two genders directly.
• A double bar graph (with side-by-side bars for males and females each year) would make direct comparison between the two genders much easier.
• This matches option C: "The stacked line chart makes it easy to see the changing total, but a double bar graph (one bar for males and one for females each year) would make the male/female comparison easier."

Answer:

Question 1

The number of college degrees awarded to males in 2020 was <blank>\(1,000,000\)</blank>.
The number of college degrees awarded to females in 2020 was <blank>\(1,100,000\)</blank>.

Question 2

They were approximately equal in <blank>1980</blank>.

Question 3

The decade in which the total number of degrees increased the most was <blank>2010–2020</blank>.

Question 4

• A. The stacked line chart makes it easy to see the exact number for each gender for every year, but a pie chart would make it easier to compare the percentages for each gender.
• B. The stacked line chart makes it easy to see the exact number for each gender for every year, but a double bar graph (one bar for males and one for females each year) would make the male/female comparison easier.
• C. The stacked line chart makes it easy to see the changing total, but a double bar graph (one bar for males and one for females each year) would make the male/female comparison easier. (Correct answer)
• D. The stacked line chart makes it easy to see the changing total, but a pie chart that would make it easier to compare the percentages for each gender.