# Math Insight

### Applet: Fitting a linear model to bacteria population change as a function of density

Bacteria population density data is plotted by the blue points in the left panel and shown as a chart in the right panel. The population density $B_t$ at time $t$ is shown as B_t in the right panel and the population change is $B_{t+1}-B_t$. By moving the point $P$ (represented by the red diamond) with the mouse, you can find a line through the origin that is close to most of the points and read off its slope.

Applet file: bacteria_density_change_versus_density_line.ggb