Assume that a perfectly competitive firm can sell as much of its product as it wants at a market price of $20. calculate total revenue and average revenue at production levels of 1000 and 1001 and marginal revenue as the firm goes from 1000 to 1001. describe the relationship among the variables."

You are thinking of making your mansion more energy efficient by replacing some of the light bulbs with compact fluorescent bulbs, and insulating part or all of your exterior walls. each compact fluorescent light bulb costs $4 and saves you an average of $2 per year in energy costs, and each square foot of wall insulation costs $1 and saves you an average of $0.20 per year in energy costs.† your mansion has 150 light fittings and 3000 sq ft of uninsulated exterior wall. to impress your friends, you would like to spend as much as possible, but save no more than $750 per year in energy costs (you are proud of your large utility bills). how many compact fluorescent light bulbs and how many square feet of insulation should you purchase? how much will you save in energy costs per year? (if an answer does not exist, enter dne.)

Alarge university wanted to study the relationship between completing an internship during college and students' future earning potential. prom the same graduating class, they selected a random sample of 80 students who completed an internship and 100 students who did not complete an internship and examined their salaries five years after graduation. they found that there was a statistically higher mean salary for the internship group than for the noninternship group. which of the following interpretations is the most appropriate? a. there could be a confounding variable, such as student major, that explains the difference in mean salary between the internship and no internship groups.b. we cannot infer anything from these data since the distribution of salaries is likely right skewed.c. you cannot draw any valid conclusions because the sample sizes are different.d. more students should complete internships because having an internship produces a higher salary.

M. cotteleer electronics supplies microcomputer circuitry to a company that incorporates microprocessors into refrigerators and other home appliances. one of the components has an annual demand of 235 units, and this is constant throughout the year. carrying cost is estimated to be $1.25 per unit per year, and the ordering (setup) cost is $21 per order. a) to minimize cost, how many units should be ordered each time an order is placed? b) how many orders per year are needed with the optimal policy? c) what is the average inventory if costs are minimized? d) suppose that the ordering cost is not $21, and cotteleer has been ordering 125 units each time an order is placed. for this order policy (of q = 125) to be optimal, determine what the ordering cost would have to be.