The table shows how far a distance runner has traveled since the race began. What is her average rate of change, in miles per hour, during the interval 0.75 to 1.00 hours?

Time Elapsed (Hours)
Miles Traveled (Miles)
0.50
2.00
0.75
3.50
1.00
4.75
4.75 miles per hour
5.00 miles per hour
5.50 miles per hour
6.00 miles per hour