What do you mean... $245???
Answer:55.227
Step-by-step explanation:
Given data
mass
=13lb
spring stretches by
=4.5in=0.375 ft
g=
Now Spring constant K
mg=kx
k=
For critical damping 

and 

substituting values

c=55.227 lb.sec/ft
0.25 since each is 1/4 of the square
4 5/9 this is the answer to your question
Since angle C is not 90 degrees, it's one of the acute angles
in the right triangle.
(The side adjacent to angle C ) divided by (hypotenuse)
is the cosine of angle C .
(adjacent) / (10 inches) = cos(40 degrees)
Multiply each side by (10 inches):
Adjacent side = (10 inches) x cos(40) =
(10 inches) x 0.766 =
7.66 inches (rounded)