Beef obviously loses water when you dehydrate it to make beef jerky. What's the ratio here? Does it take two pounds of fresh beef to make a pound of beef jerky?
It depends on how moist you like your jerky. A typical jerky loses half of its starting weight in moisture, so 2:1 is the proper ratio. "Low moisture" jerky can actually be 1/3 the starting weight, a 3:1 ratio.
So 2-3 pounds of beef will make 1 pound of jerky.