A person is walking briskly in a straight line. The figure shows a graph of the person’s position x as a function of time t. What is the person’s average velocity between t = 6 s and t = 10 s?

The average velocity over the interval [tex]6\le t\le 10[/tex] is
[tex]\dfrac{x(10)-x(6)}{10\,\mathrm s-6\,\mathrm s}=\dfrac{6\,\mathrm m-2.67\,\mathrm m}{4\,\mathrm s}=0.8325\,\dfrac{\mathrm m}{\mathrm s}[/tex]
where [tex]x(t)[/tex] is the person's position at time [tex]t[/tex]. I've taken the liberty of estimating [tex]x(6)\approx2.67\,\mathrm m[/tex]. The closest choice among the answers is [tex]0.8\,\dfrac{\mathrm m}{\mathrm s}[/tex].