The restaurant's cost equation for estimating costs if the number of guests to be served is up to 14,000 guests per month can be calculated as follows:
Fixed costs = $143,000 per month
Variable costs = $15 per guest
Total costs = Fixed costs + Variable costs x Number of guests
Total costs = $143,000 + $15 x Number of guests
If the restaurant were to serve 13,000 guests in May, the estimated total cost would be:
Total costs = $143,000 + $15 x 13,000
Total costs = $322,000
The average cost per guest would be:
Average cost per guest = Total costs / Number of guests
Average cost per guest = $322,000 / 13,000
Average cost per guest = $24.77
If the restaurant were to serve 11,000 guests in June, the estimated total cost using the cost equation from Requirement 1 would be:
Total costs = $143,000 + $15 x 11,000
Total costs = $298,000
The estimated total cost using the average per guest cost from Requirement 2b would be:
Total costs = Average cost per guest x Number of guests
Total costs = $24.77 x 11,000
Total costs = $272,470
The difference in the two cost estimates is due to the fact that the average cost per guest includes only the variable cost of food and not the fixed costs of the restaurant.
The restaurant's cost equation for estimating costs if the number of guests to be served is more than 14,000 guests per month can be calculated as follows:
Fixed costs = $143,000 + $22,000 = $165,000 per month
Variable costs = $15 per guest
Total costs = Fixed costs + Variable costs x Number of guests
Total costs = $165,000 + $15 x Number of guests
If the restaurant were to serve 15,000 guests in July, the estimated total cost would be:
Total costs = $165,000 + $15 x 15,000
Total costs = $390,000