A sample of 21 minivan electrical warranty repairs for “loose, not attached” wires (one of several electrical failure categories the dealership mechanic can select) showed a mean repair cost of $45.66 with a standard deviation of $27.79. (a) Construct a 95 percent confidence interval for the true mean repair cost. (b) How could the confidence interval be made narrower? (Data are from a project by MBA student Tim Polulak.)

Historically, money has not always been of uniform quality. for example, diamonds were often used as a form of money, but every diamond is different. what problem occurs when money is not of a uniform quality? people will hoard high-quality money and spend low-quality money. as a result, the money used in transactions will be of inferior quality. people will turn to commodity money if they don't trust paper money. people will rely on barter rather than accept money as payment. unlike pennies and nickels, which cost more to produce than they are worth, paper money and quarters are: a good store of value examples of token money useful as a medium of exchange cattle can be used as money but can also be slaughtered for food. cattle are an example of: commodity money fiat money ideal money