Ask him again and phrase the question as:
"What if I download a file (i.e. right click, save target as) and the file was 5Mb big, under the 'current file transfer rate reading' what can I expect to see"?
This is what we are looking at - the actual transfer rate at a given time.
You can do tests at:
http://speedtest.mybc.com/
http://speedtest.inch.com/
My throughput was about 450k/s but actual download rate i.e. file size divided by time taken was 53.3k/s and this is the magic number!