A homeowner recorded the amount of electricity in kilowatt-hours (kWh) consumed in his house on each of 9 days. He also recorded the numbers of hours his air conditioner was turned on (AC). From the data above, what is the correct equation of the regression line to predict the amount of electricity consumed from the number of hours the air conditioner was turned on?
a) y = 5x + 40
b) y = 10x + 20
c) y = 15x + 10
d) y = 20x + 5
