Answer:
4. IV: Temperature DV: how fast a cake will bake Constant: Same oven. Same ingredients. Same flavor. Same amounts.
5. IV: How much water? DV: How many lemons? Constant: Same type of tree, Same soil, same area
6. IV: Plant is fertilized or not. DV: Amount of bushels or potatoes. Constants: Same soil, Same type of potato, same brands of fertilizer