Final answer:
The number of weeds is decreasing by a multiplicative rate.
Step-by-step explanation:
The graph shows a downward trend in the number of weeds as the days after treatment increase. Based on the graph of the regression model, the number of weeds is decreasing by a multiplicative rate.
In an exponential decay model, the value decreases or decays at a constant percentage for each increment of the independent variable. In this case, as the days after treatment increase, the number of weeds decreases by a certain percentage each time.
For example, let's consider the data points in the table. From day 2 to day 4, the number of weeds decreases from 100 to 26. It can be observed that the value is not decreasing by a constant amount but rather by a percentage. This indicates that the number of weeds is decreasing by a multiplicative rate.