Bot Randi places 2 bags of potatoes in a bin. Each bag contains 3.5 pounds of white potatoes and 2 3/4 pounds of yellow potatoes. Randi removes 4 pounds of potatoes from the bin. How many pounds of potatoes are left in the bin?
The total weight of potatoes in each bag is 3.5 + 2 3/4 = 3.5 + 11/4 = 14/4 + 11/4 = 25/4 = 6.25 pounds.
The total weight of potatoes in the bin is 6.25 * 2 = 12.5 pounds.
After removing 4 pounds of potatoes, 12.5 - 4 = <<12.5-4=8.5>>8.5 pounds of potatoes are left in the bin. Answer: \boxed{8.5}.