A dog's position along a straight path is plotted against time…

Step 1. The three slopes. $0\ \text{s}$ to $4\ \text{s}$: $\dfrac{12\ \text{m}}{4\ \text{s}} = 3\ \text{m/s}$. $4\ \text{s}$ to $10\ \text{s}$: flat, $0\ \text{m/s}$. $10\ \text{s}$ to $14\ \text{s}$: $\dfrac{-4\ \text{m} - 12\ \text{m}}{4\ \text{s}} = -4\ \text{m/s}$.

Step 2. Average speed. Path length $12\ \text{m} + 16\ \text{m} = 28\ \text{m}$, so $\dfrac{28\ \text{m}}{14\ \text{s}} = 2.0\ \text{m/s}$.

Step 3. Average velocity. $\dfrac{-4\ \text{m} - 0\ \text{m}}{14\ \text{s}} = -0.29\ \text{m/s}$.