3. | stats  

$ cat /var/log/nginx/access.log | \
  perl -nE '/"rtt=(\d+[.]\d+)/ && say $1 * 1000' | \
  stats
Total:     4211317
Count:      123908
Mean:           33.987
Median:         20.000
Std-dev:       225.233
Minimum:         0.000
Maximum:     16127.000
Variance:    50730.037