Answer:
Amount of pork used was 1 pound.
Step-by-step explanation:
Mike wants to make meatloaf by adding beef and pork.
Ratio of the meat (beef and pork) is = 3 : 1
Recipe requires total amount of meat = 4 pounds
So the amount of pork used in the recipe = 
= 
= 1 pound
Therefore, total amount of pork used in the recipe is 1 pound.