Average monthly electric bill

Question

An electric company found the relationship between house size (x, in square feet) and monthly electric bill (y, in dollars) is given by yˆ
y
^
= 0.03x + 18.50. Use this least squares line to predict the average monthly electric bill for a house that is 2,097 square feet in size.

Answer 1

Wow, this is the friendliest question I have seen all day! The "least squares line" or "regression line" is exactly the equation you provided. The hat on y indicates that it is only an estimate of the bill, not what an actual bill ever was (whereas a "y" without one would be an electric bill we actually saw).

Simply plug the square footage into X, multiply by .03 and add 18.50.