A line of best fit predicts an output from an input. In a model written as , the coefficient and constant have different roles. Match the number the question names to its role, then use the axis labels to describe its units. Don’t swap the axes or confuse a starting prediction with a per-unit change.
Hints
- Hint 1
In a linear equation, one number multiplies , while another number is added after that product. Which job does have, and how is that different from the job of ?
- Hint 2
The input is on the horizontal axis, and the output is on the vertical axis. Which variable tells distance, and which tells predicted speed? Check those roles before matching a model number to a choice.
Step-by-step
Read the constant term
Step 1Find what the constant represents
No Desmos needed. The model already gives the intercept. A -intercept is where the line meets the vertical axis, so . In , the term becomes zero there, leaving . The line passes through . The constant term is the predicted output at zero input.
- Step 2
Put the intercept in context
Here means a distance of 0 meters from the router. The symbol means predicted download speed, not a speed measured at one plotted location. So the model predicts megabits per second at that distance. Choice A.