The linear function in slope-intercept form is expressed as:

$y = mx + b$

Where:

• $m$ is the slope of the line.
• $b$ is the y-intercept (the value of $y$ when $x = 0$).

For the data provided, the linear function is:

$y = 4.31x + 27.74$

This means that for each year after 2010, the airline revenue from add-on fees increases by approximately $4.31 billion, starting from a base of $27.74 billion in 2010.

Would you like to dive deeper into this topic or explore anything else?

Here are 5 related questions for further exploration:

1. How do you find the slope of a line if only two points are given?
2. What is the significance of the y-intercept in real-world scenarios?
3. How would the function change if the revenue trend slowed down over time?
4. Can you find the equation of a line given a point and a slope?
5. What happens to the linear function if the data shows a decrease in revenue over time?

Tip: When modeling real-world data, consider if a linear trend continues indefinitely or if other factors might alter the trend.