The final answer for this is 4x^2-25y^2.
The standard deviation of the set is 5.2
To find standard deviation, we take the square root of the variance.
Since 1/8000 is 0.000125, we can move the decimal 4 terms to the right.
So that will be 1.25 • 10^-4
Choice B
Answer is 5 hope i helped