Final answer:
To find the value of N that minimizes the costs, we can take the derivative of the total cost function with respect to N and set it equal to zero. Solving for N gives us N = sqrt(GD/T).
Step-by-step explanation:
To minimize costs, we need to determine the optimal value of T.
Since the gas station sells S gallons per year and receives N equal shipments of G gallons each year, the number of deliveries per year is given by N=S/G.
The storage time T is the length of time (a fraction of a year) between shipments and can be expressed in terms of N as T=1/N. By substituting this expression for T into the equation for the total cost, we can find the value of N that minimizes the costs:
Total cost = (delivery cost per shipment)×(number of deliveries per year) + (storage cost per gallon per year)×(total gallons per shipment)×(storage time per year)
=($D)×(N) + ($T)×(G)×(1/N)
=($D)×(N) + ($T)×(G/N)
Now, to find the optimal value of N, we can take the derivative of the total cost function concerning N and set it equal to zero:
d(Total cost)/dN = $D - ($T)×(G/N^2) = 0
Solving for N gives us:
N = sqrt(GD/T)