Pinewood Derby X Wing Velocity Question?

Velocity question? - pinewood derby x wing

The position of a traditional pinewood car has been repeatedly observed, the results in the following table. Find the average speed of the car for the following periods.

t (s) 0 1.0 2.0 3.0 4.0 5.0
X (M) 0 2.6 8.4 21.3 35.6 69.5

a. during the first second in m / s
b. in the last 3 nm / s
c. during the observation period in m / s