It signifies the excavator's weight class... it weighs appx 20 tonnes
A
it means penis
I think it is supposed to denote EXcellence
If you mean the Bobcat excavator, there is one that is about 34 inches wide.
The 315 is a model size of the excavator. Cat uses the last 2 numbers ( the 15 in the 315) . In this case the 15 means 15 metric ton. If the machine was a 320 it would be 20 metric ton and 325 would be 25 metric ton and so on. Most other brands of excavators use the first 2 numbers in the model number. Like Deere's 160 you would use the first 2 numbers the 16 and that would mean 16 metric ton and the 200 Deere would be a 20 metric ton machine and so on!
The question is vague, but they're probably the periods.
behind small square plate on right side above track
Should be behind the operator, on the right hand side of the cab, if I remember correctly.
As the house numbers are, odd numbers on one side, even numbers on the other side.
Mean is where you add up all the numbers and divide by how many numbers there are. Median is where you put the numbers in order from least to greatest and you find the middle number by crossing each side out one at a time.
The excavator of Ur, the ancient Mesopotamian civilization, was Leonard Woolley.