it is nothing but the transaction response time of 90% of 
the transaction. This is first thing we need to see once 
the summary report got opened.

It is 90th person response time out of 100.

if you arrange the 100 response times from good to bad i.e 
in ascending order.the 90 percentile response time is the 
90th response time.so if 90th response time is in the 
acceptable range since the elements are in ascending order 
we can say 90 out of 100 response times are in the 
acceptable range other 10 might be in the acceptable range 
or may not.

This is the percentage of best 90 transactions response 
time out of 100.

Hi 

90% means 90th person response time out of 100. 90 
percentile response time is the 
90th response time u can see this values in reports..


when generate the report we can see 90% means Ex One 
scripts we have 10 start and end transaction and i ran this 
test for 20 users so each user taking time Transaction 
responce time is defarent...

One Transaction (1)...ex : Navigation to_ Inbox Page 
1 users 20Sec 
2 users 78 
3 user 45
4 user 04 
5 user 12
6 user 15
7 user 25
8 user 45
9 user 12
10 user 72

this 90% means which users taking more time out of this 10 
users 72 Sec it's called 90% ...not 78% (it's Called Max)

means the result falls into the top 10% out of 100.

If 100 transactions takes place, it is the average of the 
best 90 of them.
Thanks,
Surekha

The 90th percentile tells you the value for which 90% of 
the data points are smaller and 10% are bigger. 
Statistically, to calculate the 90th percentile value:
1. Sort the transaction instances by their value.
2. Remove the top 10% instances.
3. The highest value left is the 90th percentile. 

Example:
There are ten instances of transaction "t1" with the values 
1,3,2,4,5,20,7,8,9,6 (in sec).
1. Sort by value -- 1,2,3,4,5,6,7,8,9,20.
2. Remove top 10 % -- remove the value "20."
3. The highest value left is the 90th percentile -- 9 is 
the 90th percentile value.

it is the responce time of the 90th person