When would you need to use the rule of 72?

Dodd corporation uses the weighted-average method in its process costing system. this month, the beginning inventory in the first processing department consisted of 400 units. the costs and percentage completion of these units in beginning inventory were:

After the 2008 recession, the amount of reserves in the us banking system increased. because of federal reserve actions, required reserves increased from $44 billion to $60 billion. however, banks started holding more reserves than required. by january 2009, banks were holding $900 billion in excess reserves. the federal reserve started paying interest on the excess reserves that the banks held. what possible impact will these unused reserves have on the economy?

Stock a has a beta of 1.2 and a standard deviation of 20%. stock b has a beta of 0.8 and a standard deviation of 25%. portfolio p has $200,000 consisting of $100,000 invested in stock a and $100,000 in stock b. which of the following statements is correct? (assume that the stocks are in equilibrium.) (a) stock b has a higher required rate of return than stock a. (b) portfolio p has a standard deviation of 22.5%. (c) portfolio p has a beta equal to 1.0. (d) more information is needed to determine the portfolio's beta. (e) stock a's returns are less highly correlated with the returns on most other stocks than are b's returns.