Answer:
Step-by-step explanation:
The elevation at which each started is where their respective graphs go through the y axis. Julio's graph goes through the y axis at 4 miles and Kathy's goes through at 0 miles, or in other words, on the ground.
As far as who made it to 8 miles first. Locate the 8 on the y-axis and go straight across, following that horizontal line y = 8. The first graph you run into on that horizontal line is Kathy's. Where her graph meets y = 8, drop straight down to the x-axis and see that she hit 8 miles at a little over 16 hours. Julio hit 8 miles at 18 hours.
As far as who experienced a greater elevation change...that was Kathy. She started at ground level and climbed to 9 miles, while Julio started at 4 miles and climbed to 9 miles.
