Answer:
4
Step-by-step explanation:
To find the rate of change for the increase (warm up), use the coordinate pair of any two points on the line that slopes upwards in the graph.
Let's use the following:
At 5 mins (x), heart beats (y) is 80 => (5, 80)
At 10 mins (x), heart beats (y) is 100 => (10, 100)
Rate of change = [tex] \frac{y_2 - y_1}{x_2 - x_1} [/tex]
[tex] = \frac{100 - 80}{10 - 5} [/tex]
[tex] = \frac{20}{5} = 4[/tex]
Rate of change is 4.
