Which of the following is not correct? a. the consumer price index is used to monitor changes in the cost of living over time. b. the consumer price index is used by economists to measure the inflation rate. c. the consumer price index gives economists a way of turning dollar figures into meaningful measures of purchasing power. d. the consumer price index is used to measure the quantity of goods and services that the economy is producing.

When cell phones were first entering the market, they were relatively large and reception was undependable. all cell phones were essentially the same. but as the technology developed, many competitors entered, introducing features unique to their phones. today, cell phones are only a small fraction of the size and weight of their predecessors. consumers can buy cell phones with color screens, cameras, internet access, daily planners, or voice activation (and any combination of these features). the history of the cell phone demonstrates what marketing trend?