Amount collected at the first hour = 350 x $17.50 = $6125
In the second hour, there were 20% more people:
20% of 350 = 0.2 x 350 = 70
Number of people = 350 + 70 = 420
Amount collected at the second hour = 420 x $17.50 = $7350
Total = $6125 + $7350 = $13475
Answer: $13475