Answer:
Check the explanation
Step-by-step explanation:
C(x) = 0.06x^2 - 6x + 218
Its a quadratic function , minima would occur at vertex.
x is no. of digital cameras
x = -b/2a = -(-6/2*0.06) = 50 cameras
Minimum marginal cost : C(50) = 0.06(50)^2 - 6*50 + 218 = $ 68