Answer:
The minimum value occurs at 20 fixtures and is $700
Step-by-step explanation:
C = 0.25n^2 - 10n + 800
to find the minimum we need to find the vertex
this parabola opens upwards, so the minimum is at the vertex
the vertex is at h=-b/2a where an^2 +bn+c
h = -(-10)/2*.25
h = (10/.5)
h= 20
the n value of the vertex is at 20
the find the C value, we substitute this into the equation
c(20) = .25 (20)^2 -10(20) + 800
C(20) = .25 (400) - 200 + 800
C(20) = 100 -200+800
C(20) = 700
The minimum value occurs at 20 fixtures and is $700