Find the slope of the graph.

1. (b) Find the slope of the graph.
The student's calculation for the slope is:

$$S = \frac{y_2 - y_1}{x_2 - x_1} = \frac{21.5 - 10.4}{25.5 - 11.6} = \frac{11.1}{13.9} \approx 0.79856$$

Rounding this to one decimal place, as the student did:

$$S \approx 0.8$$

The student's calculation is consistent with their final value.
The slope of the graph is $\boxed{\text{0.8}}$.

*2.