t 2 4 6 8 10 12

v(t) 44 42 41 40 37 35

the velocity in the table is decreasing 2 </= x </= 12. Using n=5 subdivisions, approximate the total distance traveled for:

a) an upper estimate
b) a lower estimate

i'm not quite sure what the question is asking. i don't understand how n=5 fits in the approximation.

They want to to add up the distances travelled during the five intervals: 2 to 4 s, 4 to 6 s, 6 to 8 s, etc.

You will get an upper estimate by using the highest (first) velocity in each interval. You will get a lower by using the lowest (last) velocity in each interval.

This does not seem like a very instructive exercise.