[daylight]

I'm really not sure if I understand this, but here is the question.
The data in the following table is for the reacion, 2N₂O₅=4NO₂ + O₂
I have a chart of like time mol/l and secons, but I'll just use two as an example:
N2O5 (mol/L)  t (seconds)
0.0152             0
0.0113             10 

I'm not sure but is the formula  average rate= -:delta:(N2O5)/ :delta:t=-(N2O5)final - (N2O5)initial/tfinal-t initial 
so would I use that  to get the average rate of reaction for each set of data??
Thanks

[daylight]

 I forgot to enter the actual probelm question and it won't let me edit for some reason...

Q: Write the equation for average rate of disappearance of dinitrogen pentoxide and calculate the average rate of reaction between each time interval.

[jotakabe]

The average rate is going to be delta [N2O5] / delta time.  Your rate should have units of M/s or mol/(L*s).  Since the reaction order is > 0, the average rate should be different between each data point.  Have fun!