How many jalapeño peppers is 3/4 pound? How many cups of chopped, seeded peppers is 3/4 pound?

I agree with SKK, but if you are in a pinch without a scale Ball canning estimates a medium Jalapeno is going to weigh about an ounce. So that would be about 12 peppers for 3/4 of a pound. Here is the Ball link: http://www.freshpreserving.com/recipe.aspx?r=247

Difficult to say given the various sizes of jalapenos. Best thing to is weigh the peppers either at the store or on your kitchen scale. The recipe doesn't call for 3/4 pounds of seeded, chopped peppers, so you will be safe weighing whole.