Question

use the four graphs shown below to answer questions 13-15.

1. lora got on the treadmill and started a run. which graph best represents her heart rate in the first minute?
2. ______
3. which graph could represent the speed of a car as it approaches a stop light?
4. ______
5. which graph best represents the download speed of a large file?
6. ______

graph a	graph of a line with positive slope starting from a point on the y-axis
graph b	graph of a line with negative slope starting from the origin
graph c	graph of a vertical line segment
graph d	graph of a line with negative slope starting from a point on the y-axis

© gina wilson (all things algebra®, llc), 2012-2018

Explanation:

Question 13:

When a person starts running on a treadmill, their heart rate typically increases over time, especially in the initial minutes as the body adjusts to the exercise. Let's analyze the graphs:

• Graph A: The line has a positive slope, meaning the value (heart rate) increases as time (x - axis) increases. This matches the scenario of heart rate increasing when starting to run.
• Graph B: Negative slope, so the value decreases over time, which doesn't fit.
• Graph C: Vertical line, which doesn't represent a typical relationship (constant time with changing value, not logical for heart rate over time).
• Graph D: Starts at zero, but when starting a run, heart rate isn't zero initially; it increases from the resting rate, so Graph A is better as it starts from a non - zero value and increases.

As a car approaches a stop light, it should slow down, so the speed of the car should decrease over time.

• Graph A: Positive slope (speed increasing), not correct.
• Graph B: Negative slope, speed decreases over time, which matches the car approaching a stop light (slowing down).
• Graph C: Vertical line, not a valid speed - time graph for this scenario.
• Graph D: Starts at zero, but a car approaching a stop light is already moving, so it should start from a non - zero speed and decrease, which Graph B does (assuming the y - axis is speed and x - axis is time, the line goes down as time increases).

When downloading a large file, the download speed can sometimes decrease as the download progresses (due to server load, network congestion, etc.), or it can be a situation where the speed starts from a certain value and decreases. Also, initially, the download speed might be at a non - zero value.

• Graph A: Positive slope (speed increasing), not typical for download speed of a large file (usually doesn't increase as download progresses).
• Graph B: Negative slope, speed decreases over time. This can be the case as the file download progresses, maybe due to factors like server resources being shared, etc.
• Graph C: Vertical line, not valid.
• Graph D: Starts at zero, but when you start downloading a large file, the speed is non - zero (starts with the available bandwidth speed), so Graph B is a better representation as it shows a decrease from a non - zero initial speed.

Answer:

Graph A

Question 14: