Answer:
a)420,491.1 b) 420.49 c) 429.68 d) 900 e) 420
Step-by-step explanation:
A) Replace x = 1000 in the cost function
C (1000) = 54,000 + 240*1000 + 4*1000^(3/2)
C (1000) = 420,491.1
B) Average cost per unit is c(x) = C(x)/x
420,491.1/1000 = 420.49
C) Marginal cost is the additional cost to produce a unit, so we find the cost difference between producing 999 and 1000 units
C (999) = 54,000 + 240*999 + 4*999^(3/2)
C (999) = 420,061.41
Marginal cost = 420,491.1 - 420,061.41 = 429.68
D) To find the minimum value for units, we find the derivate of average cost function and equal to zero
C(x)/x = 54000/x + 240*x/x + 4*x^(3/2)/x
C(x)/x = 54000*x^(-1) + 240 + 4*x^(1/2)
C’(x)/x = -54000*x^(-2) + 4*(1/2)*x^(-1/2)
C’(x)/x = -54000/x^(2) + 2/x^(1/2)
Equal to zero
-54000/x^(2) + 2/x^(1/2) = 0
2/x^(1/2) = 54000/x^(2)
x^(2) / x^(1/2) = 54000/2
x^ (3/2) = 27000
x = 900
E) The minimun average cost is obtained replacing 900 in the function cost
C (900)/900 = (54,000 + 240*900 + 4*900^(3/2))/900
C (900)/900 = 378000/900 = 420