Answer:
30.8 million
Explanation:
You want the "y-intercept" of the graph of a population that is predicted to be 30.8 million in 2010 and increase at 1 per year until 2030.
Initial value
The term "y-intercept" refers to the point on a graph where the curve crosses the y-axis. The x-value at that point is zero. For graphs plotted with x = time, the y-intercept is the "initial value," the value when time is considered to be zero.
In the situation described, we presume that the domain of interest is years between 2010 and 2030, and that x=0 corresponds to the year 2010. That means the "initial value", or y-intercept, will be the population in 2010.
The value of the y-intercept is 30.8 million.
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Additional comment
We don't know the units associated with the increase of "1 per year." In this scenario, that could be 1 person, 1 million persons, or 1% of the current population. For the purpose of identifying the y-intercept, it doesn't matter. If any calculation of population is to be made, the problem statement needs further elaboration.