How to find no of occurances Finding average time?

Hi,
I have MyLog.log file, and it contains "*** response Time 150",
I want to develop Unix script like ,

  1. extract all such occurances in the MyLog.log file and
  2. compute the average time taken

I am new to Unix, any one can give any idea/sample code for this?
Thanks in advance.

pls post a snippet from your log file containing the "times".