Answer:
y=450
Step-by-step explanation:
It is given that the fixed monthly cost is $200,000, and it costs $450 to produce one refrigerator.
Total cost of x refrigerator is

The average cost function to produce X refrigerators is represented by:

If the degree of numerator and denominator are same, then horizontal asymptote is

where, p is the leading coefficient of numerator and q is leading coefficient of denominator.
In the above function leading coefficient of numerator is 450 and leading coefficient of denominator is 1. So, horizontal asymptote is


Therefore, the horizontal asymptote of C(x) is y=450.