The most appropriate answer is D !!
if you need explanation, comment ! or it's OK ! I guess it is D !
9950x=8650x+250000
Subtract 8650x from both sides
1300x= 250000
I hope you can see it just try to zoom in
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
