What does the RTTSum and RTTSum2 represent in a ASA SLA monitor?

Question

I have enabled the SLA monitor on an ASA, and I was wondering what the RTTSum and RTTSum2 Metric Represents?

RTT stands for "Rout Trip Time" I am having trouble figuring what the RTTSum actually represent, how would I read it and apply it to troubleshooting?

Modification time: 16:46:11.982 EST Mon Sep 16 2013
Number of Octets Used by this Entry: 1480
Number of operations attempted: 197
Number of operations skipped: 0
Current seconds left in Life: Forever
Operational state of entry: Active
Last time this entry was reset: Never
Connection loss occurred: FALSE
Timeout occurred: FALSE
Over thresholds occurred: FALSE
Latest RTT (milliseconds): 10
Latest operation start time: 17:18:51.982 EST Mon Sep 16 2013
Latest operation return code: OK
RTT Values:
RTTAvg: 10  RTTMin: 10  RTTMax: 10
NumOfRTT: 3 RTTSum: 30  RTTSum2: 300

And another example

Number of Octets Used by this Entry: 1480
Number of operations attempted: 243
Number of operations skipped: 0
Current seconds left in Life: Forever
Operational state of entry: Active
Last time this entry was reset: Never
Connection loss occurred: FALSE
Timeout occurred: FALSE
Over thresholds occurred: FALSE
Latest RTT (milliseconds): 13
Latest operation start time: 17:26:31.992 EST Mon Sep 16 2013
Latest operation return code: OK
RTT Values:
RTTAvg: 13  RTTMin: 10  RTTMax: 20
NumOfRTT: 3 RTTSum: 40  RTTSum2: 600

Thanks

Answer 1

RTTSum is the sum of samples, divide it by sample count and you've got arithmetic mean.

RTTSum2 is sum of squares of samples, you need it for example to derive standard deviation.