College graduates earn much more, on average, than high school graduates. research done in the us finds that high school grads over an adult's working life earn an average of $1.2 million, associate's degree holders earn about $1.6 million, and bachelor's degree holders earn about $2.1 million. according to economists, this difference in earnings is mostly due to
a) compensating differentials
b) having network connections
c) differences in human capital
d)luck

An allergy products superstore buys 6000 of their most popular model of air filters each year. the price of the air filters is $18. the cost of ordering and receiving shipments is $12 per order. accounting estimates annual carrying costs are 20% of the price. the supplier lead time is 2 days. the store operates 240 days per year. each order is received from the supplier in a single delivery. there are no quantity discounts. what is the store’s minimum total annual cost of placing orders & carrying inventory?