Answer:
2.0
Step-by-step explanation:
Couldn't really understnd what you wrote but I'll assume it's the standard deviation of a fair, 7-sided die
The standard deviation is just the square root of the variance (which is just the second moment minus the first moment squared)
The first moment (AKA the average is..)
[tex]\frac{1+2+3+4+5+6+7}{7}=4[/tex]
The second moment is..
[tex]\frac{1^2+2^2+3^2+4^2+5^2+6^2+7^2}{7}=20[/tex]
[tex]\sqrt{20-4^2}=2[/tex]
