Help with physics, velocity ...?

i am taking physics gr 11 and i need an answer to that question ASAP plz.... this question is about this rocket..here is a picture of my graph..plz help! the complete question is compare the instantenous velocities that you calculated for times 7 s , 13 s , 21 s , and 25 s. with the average velocities for... show more i am taking physics gr 11 and i need an answer to that question ASAP plz....

this question is about this rocket..here is a picture of my graph..plz help!

the complete question is

compare the instantenous velocities that you calculated for times 7 s , 13 s , 21 s , and 25 s. with the average velocities for the intervals that inclused those times In which case is the instantaneous and average velocities nearly the same? quite different? explain why..

here is the picture of the graph http://123pichosting.com/viewer.php...
Update: i did try!! LOL i jsut dont get it..some one plz tell me at least how to do it
Update 2: http://123pichosting.com/viewer.php?id=9002untitled.JPG
2 answers 2