Final answer:
The underage cost at the cafeteria, when a scone is not available and a bag of chips is sold instead, is calculated as the difference in profit from a scone versus that from the chips. This equates to a $0.15 loss for each scone that is understocked before 3 pm.
Step-by-step explanation:
The underage cost refers to the opportunity loss when the demand is higher than the supply on hand, which in this case is when a customer wants a scone before 3 pm but the cafeteria has run out, and they buy a bag of chips instead. Given the information that scones are sold for $1.50 each and the chips for $1, with purchase costs being $0.75 for a scone and $0.40 for a bag of chips, the underage cost per incident is the lost revenue from the higher-priced item minus the cost of the item not sold plus the revenue from the chips minus the cost to purchase them.
The calculation of this cost takes into account the difference in selling price and cost of both items. For each scone not available, the cafeteria loses ($1.50 - $0.75) but then gains ($1 - $0.40) from selling chips. Therefore, the underage cost per scone would be ($0.75 - $0.60) which equals $0.15.