Answer:
No, the polygons aren't similar since they don't have a constant scale factor.
Answer:
x+2
Step-by-step explanation:
The firs 3 observations are x, x+2, x+4
Mean = sum of data/samaple size
Mean = x+x+2+x+4/3
MEan = 3x+6/3
Mean = 3(x+2)/3
Mean = x+2
Hence the required mean is x+2
It is irrational. Otherwise sqrt(2) would be rational too which is not true.

I guess that is the answer.
Hope this helps !
Photon