Answer
The slope of the secant line: m$=60$
represents the average velocity of the object over the time interval $[0.5, 2 ]$.
Work Step by Step
Graph s(t) by building a table of function values.
Plot the points and draw a smooth curve through them.
See image.
The slope of the secant line:
m= $\displaystyle \frac{s(2)-s(0.5)}{2-0.5}= \displaystyle \frac{136-46}{1.5}=60$.
This represents the average velocity of the object over the time interval $[0.5, 2 ]$.