91Ó°ÊÓ

It is stated in the regression line question that,

$\stackrel{Áåœ}{y}=1425−19.87x$

As we know, the slope in the least square regression equation is the coefficient of $x$ and indicates the average rise or decrease of $y$ per unit of $x$ Thus, the slope is,

$b_1=19.87$

As a result, the average amount of natural gas Joan will consume per day over the course of a month reduces by $19.87$ cubic feet per degree Fahrenheit.

The $y-$intercept, as we all know, is a constant in the least square regression equation that reflects the average $y-$value when $x$ is $0$ As a result, the $y-$intercept is:

$b_0=1425$

When the temperature is $0$ degrees Fahrenheit, this means that the average amount of natural gas utilized per day is $1425$ cubic feet. The $y-$intercept has meaning in this instance because a temperature of $0$ degrees Fahrenheit is feasible.