The given linear function is:

$G(d) = -0.2d + 13$

where $G(d)$ represents the amount of gas in gallons, and $d$ represents the miles traveled since the last time the car was at the gas station.

Slope interpretation:

• The slope of the equation is $-0.2$, which means that for every additional mile traveled, the amount of gas in the car decreases by 0.2 gallons.

Thus, the accurate interpretation of the slope is:

"We are losing 0.2 gallons of gas every mile."

This corresponds to the third option in the image.

Would you like further details or explanations?

Here are five follow-up questions:

1. What is the interpretation of the y-intercept in this equation?
2. How do we calculate the total distance traveled before the gas runs out?
3. How would the graph of this function look like?
4. What is the physical meaning of the slope being negative?
5. How can we modify the equation if the fuel efficiency changes?

Tip: The slope in a linear equation like this often represents a rate of change in a real-world context.