Let's convert everyone into feet per second (ft/s)
Jessica : 8ft/s
Debbie: 637ft/49s = 13ft/s
Katie: 5280ft/511s = 10.33ft/s (1 mile equals 5280 feet)
Tony: 550ft/60s = 9.16ft/s (1 mile equals 5280 feet, 1 minute equals 60 seconds)
Jessica runs the fastest.