Nora is starting a business. If she invests X dollars, she will be able to sell the business for 100 dollars, which means the marginal benefit of an additional dollar of investment is 50/. Nora's net profit will be 100 - X. How much should she invest, and how much profit will she earn? Now suppose Nora is overconfident: she believes she will be able to sell the business for $200, which means she thinks the marginal benefit of an additional dollar of investment is 100/. How much will she invest? What level of profit will she expect to earn? How much profit will she actually earn? By how much does her overconfidence reduce her profit?