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*will mark brainliest! * when a company spends resources (labor, money) to give customers "free" items, those costs are called a. investment costs b. economic costs c. scarcity costs d. opportunity costs answer asap!

The usa today reports that the average expenditure on valentine's day is $100.89. do male and female consumers differ in the amounts they spend? the average expenditure in a sample survey of 47 male consumers was $135.67, and the average expenditure in a sample survey of 38 female consumers was $68.64. based on past surveys, the standard deviation for male consumers is assumed to be $34, and the standard deviation for female consumers is assumed to be $17.

Wo firms, a and b, each currently dump 50 tons of chemicals into the local river. the government has decided to reduce the pollution and from now on will require a pollution permit for each ton of pollution dumped into the river. it costs firm a $100 for each ton of pollution that it eliminates before it reaches the river, and it costs firm b $50 for each ton of pollution that it eliminates before it reaches the river. the government gives each firm 20 pollution permits. government officials are not sure whether to allow the firms to buy or sell the pollution permits to each other. what is the total cost of reducing pollution if firms are not allowed to buy and sell pollution permits from each other? what is the total cost of reducing pollution if the firms are allowed to buy and sell permits from each other? a. $3,000; $1,500 b. $4,500; $3,500 c. $4,500; $4,000 d. $4,500; $2,500