Which of the following is an example of the 80/20 rule (in Pareto)?
1) Only a few kinds of parts in an automotive store make up most of the inventory
2) Mufflers, fan belts, and spark plugs are the most common parts in an automotive store
3) The 80/20 rule states that 80% of the effects come from 20% of the causes
4) The 80/20 rule is also known as the Pareto principle