content distribution in polymix-4 - some confusion

It is written at
http://www.measurement-factory.com/results/public/cacheoff/N04/report.by
-alph.html#Sec:Polygraph that polymix-4 uses the following statistic:

 

Images:             65%      4.5KB size

HTML:               15%      8.5KB

Download:         0.5%     300KB

Other:               19.5%   25KB

 

 

Average of these is: A=10.575KB

 

Also 85% are regular request and 15% are IMS. Among IMS, 66% requires
complete response.

 

So calculating the final expected average response size, we should get:

 

 

A*0.85 + 0*.15*.33+ A*.15*.66 = 10KB

 

However in "Reply size" section, average size is said to be 6.8KB. How
is it possible?

 

Thanks,

Serge