Difficulty is defined by (a) frequency of use, (b) frequency of spelling pattern, and (c) developmental norms. It is not difficult, then, for teachers to place students with words of appropriate difficulty based on simple measures of instructional level (Schlagal, 1996).
If one assumes that shifts in the supply curve of ethanol are solely due to the changing price of corn, then, up to an ethanol price of $2.90, the price of corn completely determines the price of ethanol. In other words, the price of corn drives the price of ethanol, not the other way around. This is actually quite logical since the amount of ethanol used is essentially fixed; consequently, something else must be driving the price of ethanol.
âLast year, the Congressional Budget Office reported that the cost to taxpayers of using corn ethanol to reduce gasoline consumption by one gallon is $1.78. This year, the corn ethanol sector will produce about 13.8 billion gallons of ethanol, the energy equivalent of about 9.1 billion gallons of gasoline.