Answer
The average velocity is $~~3.5~m/s$
Work Step by Step
We can find the area under the velocity versus time graph from $t = 0$ to $t = 1.0~s$:
$A = \frac{1}{2}(1.0~s)(2.0~m/s) = 1.0~m$
The coordinate of the particle at $t = 1.0~s$ is $1.0~m$
In part (a), we found that the coordinate of the particle at $t = 5.0~s$ is $15.0~m$
We can find the average velocity between $t = 1.0~s$ and $t = 5.0~s$:
$v_{ave} = \frac{\Delta x}{\Delta t} = \frac{15.0~m-1.0~m}{5.0~s-1.0~s} = \frac{14.0~m}{4.0~s} = 3.5~m/s$
The average velocity is $~~3.5~m/s$.
