Problem:
Donald Erickson uses gas to heat his home. He has accumulated the following information regarding his monthly gas bill and monthly heating degree-days. The heating degree-days value for a month is found by first subtracting the average temperature for each day from 65 degrees and then summing these daily amounts together for the month.
Heating
Month Degree-Days Gas Bill
January 1,800 $162
April 600 $66
What will be the increase in Donald's monthly gas bill per heating degree-day using the high-low method?