Question

(5.25) 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. He then computed the least-squares regression line for predicting y from x and found it to be

Answer 1

This question is incomplete, the complete question is;

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 65oF) over a 23-month period.

He then computed the least-squares regression line for predicting y from x and found it to be:   y^=80+16x.  

How much, on average, does gas used increase for each additional degree-day?

Answer : ______ cubic feet.

(Give your answer as a whole number.)

Answer:

Amount of natural gas used increased by 19 cubic feet.

Step-by-step explanation:

Given the data in the question;

Let the dependent variable y be the amount of natural gas used ( ft³ )

Also let an independent variable x be be the degree days temperature ( in °F)

So the least squares regression equation is;

$y^{bar}$ = 80 + 16x

or

amount_of_natural_gas_used = 80 + 16(degree_days_temperature

Th slope or the standardized regression coefficient of the given regression equation is;

b₁ = 16

the slope coefficient b₁ = 16 is tells us that for each additional one-degree days temperature, an amount of natural gas used increased by 19 cubic feet.

Therefore, amount of natural gas used increased by 19 cubic feet.