Final answer:
We can add a point representing Lin's elevation at 3 pm on a graph by placing it lower than her elevation at 2 pm and horizontally in line with the 3 pm time mark. Without specifics, we assume a linear and continuous descent.
Step-by-step explanation:
The student's question pertains to plotting a point on a graph that represents Lin's elevation at 3 pm, given that she has been climbing downward from 2 pm to 3 pm. To plot this point, we must consider the elevation Lin started from at 2 pm and the rate at which she descended. Without the specifics of Lin's starting elevation and descent rate, we cannot pinpoint an exact location on the graph. However, if we assume that Lin started at a higher elevation at 2 pm, then at 3 pm, her elevation would be lower on the vertical axis of the graph. The point would be placed vertically below her starting elevation mark, and horizontally in line with the 3 pm time mark, reflecting the downward movement.
To add a point to the graph, we assume Lin’s descent is continuous and linear over the hour so the new point would be directly under the point at 2 pm but lower depending on her rate of descent. This represents a change in elevation (a drop), which corresponds to a negative "Rise" in mathematical terms when calculating slope, similar to the examples provided in the initial information.