Answer:
As the variable cost increased by $2.10 per book so if publisher wants to start making profit at same level of production then it should increase the selling price of the book by $2.10. As the increase in cost and selling price will be same so the publisher will also start making profit at same production level. 
 
        
             
        
        
        
Answer:
Payment id received for merchanise sold on account
 
        
             
        
        
        
Answer:
Case explained below
Explanation:
Development economics is a branch of economics which deals with economic aspects of the development process in low income countries. Its focus is not only on methods of promoting economic development, economic growth and structural change but also on improving the potential for the mass of the population, either through health, education and workplace conditions, whether through public or private channels.
Development economics must encompass the study of institutional, political, and social as well as economic mechanisms for modernizing an economy while eliminating absolute poverty and transforming states of mind as well as physical condition.
 
        
             
        
        
        
Answer:
False
Explanation:
Have you ever heard the phrase "there are lies, [email protected] lies and statistics"?
The only way that a statistical study be 100% confident is that it involves everyone or everything. For example, if you want to carry on a study about how many US college students drive, in order to be 100% confident of the result, you would need to interview all the college students in the country. 
 
        
             
        
        
        
Answer:  B. The firm would install the filter at a cost of $ 300,000.
Explanation:
If the community owns the property rights, they would be able to demand that the firm pay the external cost of $500,000 per year.
If on the other hand the company installed a filter, it would cost them $300,000 but then they would not have to pay the community the $500,000. 
The lower cost option would be to install the filter for $300,000 which is what the firm would do.