The point (4, 270) represents the distance from Dallas in miles, d, after 4 hours since Travis left Pecos.
In this scenario, Roy and Travis are traveling towards each other on a highway between Dallas and Pecos. Roy is located 30 miles from Dallas and Travis is located in Pecos. They both plan to meet along the highway to exchange the key to a treasure chest. The distance from Dallas, d, is a function of the number of hours, h, since Travis left Pecos. This means that the distance from Dallas will change based on the number of hours that have passed since Travis left Pecos.
The point (4, 270) represents a specific point on the distance from Dallas versus hours since Travis left Pecos graph. It indicates that after 4 hours since Travis left Pecos, the distance from Dallas is 270 miles. This means that at this point in time, Roy and Travis are both located 270 miles from Dallas and are traveling towards each other on the highway.