Cari German uses gas to heat her home. She has accumulated the following information regarding her 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. Month Heating Degree-Days Gas Bill February 1,900 $254 April 600 $101 The equation representing the relationship between the gas bill (Y) and heating degree-days (X) is