In the 1st pair of fours the 4 on the left side is 10 times greater than the 4 on the right. The same thing with the 2nd pair of fours. The 4 on the left side is 10 greater than the 4 on the right. Hope this helps!
So, f[x] = 1/4x^2 - 1/2Ln(x)
<span>thus f'[x] = 1/4*2x - 1/2*(1/x) = x/2 - 1/2x </span>
<span>thus f'[x]^2 = (x^2)/4 - 2*(x/2)*(1/2x) + 1/(4x^2) = (x^2)/4 - 1/2 + 1/(4x^2) </span>
<span>thus f'[x]^2 + 1 = (x^2)/4 + 1/2 + 1/(4x^2) = (x/2 + 1/2x)^2 </span>
<span>thus Sqrt[...] = (x/2 + 1/2x) </span>
ANSWER

EXPLANATION
The vertex of the graph is at

The equation of the graph in vertex form is given by the formula,

The above graph has a minimum point, hence

When we put these values into the equation we obtain,

This implies that,

The point (-2,0) lies on the line.



The correct answer is D.
The table is missing in the question. The table is attached below.
Solution :
Let X = appraised value
Y = area (square feet)
The regression line is given by :







The regression line is :

To estimate the error variance, we have:
Error variance, 


The answer to this question is 12