Answer:
10
Step-by-step explanation:
If there is a direct relation between two variables x and y then it can be represented as
y = kx ,
where y is dependent variable
x is independent variable
k is constant of variation
_____________________________
First condition
y = 400
x = r
using y = kx then relationship will be
400 = kr
finding k here
k = 400/r
Second condition
y = r
x = 4
using y = kx then relationship will be
r = 4k
finding k
k = r/4
since in both condition equation is same
thus, value of k will also be same
thus,
400/r = r/4
=> 400*4 = r*r
=> 1600 = r^2

Thus, 40 is the value of r
k = r/4 = 40/4 = 10
Thus, constant of variation is 10 which is correct choice.
To cross validate
k = 400/r = 400/40 = 10
Answer:
a.) C(q) = -(1/4)*q^3 + 3q^2 - 12q + OH b.) $170
Step-by-step explanation:
(a) Marginal cost is defined as the decrease or increase in total production cost if output is increased by one more unit. Mathematically:
Marginal cost (MC) = change in total cost/change in quantity
Therefore, to derive the equation for total production cost, we need to integrate the equation of marginal cost with respect to quantity. Thus:
Total cost (C) = Integral [3(q-4)^2] dq = -(1/4)*(q-4)^3 + k
where k is a constant.
The overhead (OH) = C(0) = -(1/4)*(0-4)^3 + k = -16 + k
C(q) = -(1/4)*(q^3 - 12q^2 + 48q - 64) + k = -(1/4)*q^3 + 3q^2 - 12q -16 + k
Thus:
C(q) = -(1/4)*q^3 + 3q^2 - 12q + OH
(b) C(14) = -(1/4)*14^3 + 3*14^2 - 12*14 + 436 = -686 + 588 - 168 + 436 = $170
Answer:

Weight of the truck=9408 N
Step-by-step explanation:
Boat is experiencing the buoyant force as it is in the water and is sinking
According to the force balance in y direction. As both is floating, two forces balance each other:

where:
is the buoyant force
is the weight=mg
Eq (1)
Buoyant force is equal to the mass of water displaced * gravitational acceleration.

Taking density of water to be 1000 Kg/m^3

From Eq(1):

Weight of the truck=9408 N
Answer:
<em>The amount of animal feed left was 86.4 kilograms.</em>
Step-by-step explanation:
Initial amount of animal feed in the barn was 96 kilograms.
The barn leaked and
of the feed was wasted.
So, <u>the amount of feed wasted</u>
kilograms.
<em>Now, for finding the amount of feed that was left, we need to subtract the amount of wasted feed from the initial amount of feed.</em>
So, the amount of animal feed left 
Answer:
He moved 6 floors up, then moved 8 floors down. So he is now 2 floors below ground level.
I hope this helps.
Step-by-step explanation: