[httperf] httperf measurement for probabilites

[Bhagwan Anjanappa]

Hi Martin,
     I came across a paper which uses httperf to test a shopping cart 
application here it says 

"Each client session follows a simple pattern: go to main page, sign 
in, browse products, add some products to shopping cart, check out, 
repeat. Two parameters indirectly define the number of operations 
within a session. One is the probability that an item is added to the 
shopping cart given that it has just been browsed. The other is the 
probability of proceeding to the checkout given that an item has just 
been added to the cart. These probabilities vary sinusoidally between 
0.42 and 0.7 with periods of 67 and 73 minutes, respectively"

How were the probabilites found? the numbers they give have been 
collected after the testing.