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.
Average Rack Prices. As of August 2015, the rack price of ethanol was $1.62 versus $2.19 for unleaded 87âoctane gasolineâa difference of 57 cents per gallon. The average ethanol rack price fell 5 cents from last month's price and was 62 cents lower than a year ago.