What is the weighted average cost of capital? What affects it?

MINI CASE 

Assume that you recently graduated with a degree in finance and have just reported to work as an investment advisor at the brokerage firm of Balik and Kiefer Inc. One of the firm’s clients is Michelle Dellatorre, a professional tennis player who has just come to the United States from Chile. Dellatorre is a highly ranked tennis player who would like to start a company to produce and market apparel that she designs. She also expects to invest substantial amounts of money through Balik and Kiefer. Dellatorre is also very bright, and, therefore, she would like to understand, in general terms, what will happen to her money. Your boss has developed the following set of questions which you must ask and answer to explain the U.S. financial system to Dellatorre