MADD (Mothers against Drunk Drivers) has lobbied for tougher laws against drunk drivers for years. Assume that it was successful in convincing the legislators in your state to pass a tougher law...

MADD (Mothers against Drunk Drivers) has lobbied for tougher laws against drunk drivers for years. Assume that it was successful in convincing the legislators in your state to pass a tougher law against drunk drivers that required a mandatory jail sentence of at least 6 months, loss of driver’s license for 5 years, and a fine of at least $10,000. You want to test the effect of this tougher law, so you record the number of people arrested and convicted for DUI (driving under the influence of alcohol) for 5 years prior to the passage of this law and for 5 years after passage of this law. You find that the number of arrests and convictions decreased after the law was passed, so you conclude that the tougher laws are effective.