Which of the following is true? a. voluntary trades give both parties more in value than what they give up. b. people can gain by specializing in the production of the good in which they have a comparative advantage. c. all of the above are true. d. without the ability to trade, people would not tend to specialize in those areas where they had a comparative advantage. e. voluntary trade directly increases wealth by making both parties better off, and it is the prospect of wealth-increasing exchange that leads to productive specialization.

Bandar industries berhad of malaysia manufactures sporting equipment. one of the company’s products, a football helmet for the north american market, requires a special plastic. during the quarter ending june 30, the company manufactured 35,000 helmets, using 22,500 kilograms of plastic. the plastic cost the company $171,000. according to the standard cost card, each helmet should require 0.6 kilograms of plastic, at a cost of $8 per kilogram. 1. what is the standard quantity of kilograms of plastic (sq) that is allowed to make 35,000 helmets? 2. what is the standard materials cost allowed (sq x sp) to make 35,000 helmets? 3. what is the materials spending variance? 4. what is the materials price variance and the materials quantity variance?