5,000,000 is the total amount of the 4 years: both public and private. (see the second graph, you do have 4 categories, actually).
But we only should care about of private 4-years. From the second graph, we do know that this category is the 22% of 5,000,000, which means we have 1,100,000 enrollments.
The first graph starts from 80 (the private 4-year) to 120
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From what you see we have about a % increase of circa 50 %. This is a question that tastes your knowledge of the percent increase or decreases.
100 increased by 50% becomes 150%
here in a similar fashion, we do have that 1,100,000 plus 50% more is about answer choice E.
Hope now is clear to you.
Regards