Marci Johnson 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.
The equation representing the relationship between the gas bill (Y) and heating degree-days (X) is:

Question

Marci Johnson 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.
 The equation representing the relationship between the gas bill (Y) and heating degree-days (X) is:

Quizplus · Accepted Answer

($129 - $52) / (850- 300) = $0.14 = variable cost per heating degree day
$129 - (850 × $0.14) = $10 or $52 - (300 × $0.14) = $10 = fixed costs
Therefore, Y = $10 + $0.14X

Marci Johnson Uses Gas to Heat Her Home