Abusiness student conjectures that the internet caused companies to become more profitable, since many transactions previously handled “face-to-face” could now be completed online. the student compares earnings from a sample of companies from the 1980s to a sample from the 2000s. explain why this is an observational study. if indeed profitability increased, can she conclude the internet was the cause? why or why not?

The prebisch–singer hypothesis concludes that: a. technology lowers the cost of manufactured products, so developing countries should see an increase in their terms of trade. b. developing countries experience a long-run decline in their terms of trade, as the demand for primary products in higher-income countries declines relative to their demand for manufactured goods. c. because of unfair trading practices, labor in developing countries is exploited. d. opec has been responsible for a slowdown in the world's standard of living.

You hold a diversified $100,000 portfolio consisting of 20 stocks with $5,000 invested in each. the portfolio's beta is 1.12. you plan to sell a stock with b = 0.90 and use the proceeds to buy a new stock with b = 1.50. what will the portfolio's new beta be? do not round your intermediate calculations.

The gilbert instrument corporation is considering replacing the wood steamer it currently uses to shape guitar sides. the steamer has 6 years of remaining life. if kept,the steamer will have depreciaiton expenses of $650 for five years and $325 for the sixthyear. its current book value is $3,575, and it can be sold on an internet auction site for$4,150 at this time. if the old steamer is not replaced, it can be sold for $800 at the endof its useful life. gilbert is considering purchasing the side steamer 3000, a higher-end steamer, whichcosts $12,000 and has an estimated useful life of 6 years with an estimated salvage value of$1,500. this steamer falls into the macrs 5-year class, so the applicable depreciationrates are 20.00%, 32.00%, 19.20%, 11.52%, 11.52%, and 5.76%. the new steamer is fasterand allows for an output expansion, so sales would rise by $2,000 per year; the newmachine's much greater efficiency would reduce operating expenses by $1,900 per year.to support the greater sales, the new machine would require that inventories increase by$2,900, but accounts payable would simultaneously increase by $700. gilbert's marginalfederal-plus-state tax rate is 40%, and its wacc is 15%.a. should it replace the old steamer? b. npv of replace = $2,083.51