The answers are:
1. The dependent variable is distance as it varies with the reading time interval of 30 minutes.
2. The independent variable is the elapsed time with a fixed interval of 30 minutes.
3. Natalie had run approximately 8 Km in 40 minutes, marked in the graph. So she must have run, 15-8=7 Km after 40 minutes.
4. To calculate: Average speed, Given: Total distance = 15 Km, Total time elapsed = 150 minutes.
Time in hours will be [tex] \frac{150 minutes}{60 minutes} = \frac{15}{6} [/tex]
[tex] Average speed = \frac{Distance}{Time} = \frac{15 \times 6}{15} = 6 Kmh^{-1} [/tex]
