A hotel pays the phone company $100 per month plus $0.35 for each call made. During January 8,000 calls were made. In February 4,000 calls were made.

a) Calculate the hotel's phone bills for: January February.

b) Calculate the cost per phone call in: January February

c) Separate the January phone bill into its fixed and variable components.

fixed component:

variable component:

total $$

d) What is the marginal cost of one additional phone call in January?

e) What was the average cost of a phone call in January?