An owner of a home in the Midwest installed solar panels to

An owner of a home in the Midwest installed solar panels to reduce heating costs. After installing the solar panels, he measured the amount of natural gas used y (in cubic feet) to heat the home and outside temperature x (in degree days, where a day\'s degree-days are the number of degrees its average temperature falls below 65 degrees F) over a 23-month period. By looking at the equation of the least-squares regression line ( = 85 + 16x), you can see that the correlation between amount of gas used and degree-days is

Solution

If the slope is greater than 0, then the correlation is greater than 0. [And so is the same if it is less than 0.]

Thus, here, y = 85 + 16x, then

slope = 16 > 0.

Thus, the correlation is GREATER THAN 0. [ANSWER]