Based on the description of the graph, it sounds like the population of the invasive species begins at a certain point on the y-axis when the college roommates start recording data. Since the line begins flat at the bottom of quadrant 2 and passes through the y-axis, it suggests that the population is starting from a low number.
Without an actual image to reference, it's difficult to provide an exact numerical answer. However, if we assume the starting population is plotted at a specific point on the y-axis at the time of recording, rounding to the nearest tens would typically be done from the y-coordinate at that point.
If, for example, the y-value (population) indicates 12, it would round to 10. If it indicates 26, it would round to 30.
If you provide a specific value or any additional details from the graph, I can help provide a more accurate answer based on the given data.