No, It's not.
coefficients for perfect square would be:
3² - 2(3)(6) + 6² = 9 - 36 + 36
The answer is C. 8 units what you need to do is count how much from the starting point P is 4 units from A. simply double it by 2 to the new point to get 8 units.<span />
The formula for the standard error is this:
σM = σ / √N
where
σM is the standard error
σ is the standard deviation
N is the number of samples
So,
σM = 0.45 / √50
σM = 0.0636 or 6.36%
The standard error is 0.0636