Solution:
Let x the number of headsets produced
f(x) the total cost for producing x headsets
f(x) = 150000 + 0.17x
the average cost of headset c(x) is
c(x) = f(x)/x
that is:
c(x) = 150,000/x + 0.17
the graph of this function is:
now, we need to find x such that c(x) < 5, that is:
150000/x + 0.17 < 5
by solving we find
x > 31,055 headsets
we can conclude that the correct answer is:
and
x > 31,055 headsets
