What is the key to successful investing?

Marvin wrote a check of $58.25 for the water bill and $450 for rent. he also made a deposit of $124.16. how much is his new balance after writing the checks and making the deposit?

Stocks a, b, and c are similar in some respects: each has an expected return of 10% and a standard deviation of 25%. stocks a and b have returns that are independent of one another; i.e., their correlation coefficient, r, equals zero. stocks a and c have returns that are negatively correlated with one another; i.e., r is less than 0. portfolio ab is a portfolio with half of its money invested in stock a and half in stock b. portfolio ac is a portfolio with half of its money invested in stock a and half invested in stock c. which of the following statements is correct? a. portfolio ab has a standard deviation that is greater than 25%.b. portfolio ac has an expected return that is less than 10%.c. portfolio ac has a standard deviation that is less than 25%.d. portfolio ab has a standard deviation that is equal to 25%.e. portfolio ac has an expected return that is greater than 25%.

When used-car dealers signal the quality of a used car with a warranty, a. buyers believe the signal because the cost of a false signal is high b. it is not rational to believe the signal because some used-car dealers are crooked c. the demand for lemons is eliminated d. the price of a lemon rises above the price of a good used car because warranty costs on lemons are greater than warranty costs on good used cars