Question

(careful - the #2 and #3 are only from the example in the book. you are looking for the distance at which the difference between the p - and s - curves equals the time interval you found above. be sure to use the bottom scale for miles or figure 5.14 in your book)
travel - time graph
1800 miles
1500 miles
1000 miles
2500 miles

Explanation:

Step1: Locate time - interval on graph

Find the time - interval difference between P - and S - curves on the graph.

Step2: Read distance value

Using the bottom scale for miles on the graph, read the distance at which the time - interval difference is met.

Answer:

2500 miles