Above we calculated the risk of alcohol-related problems for firefighters involved in 9/11 response and for firefighters not involved. For a 9/11 first-responder, the probability of alcohol-related problems is 0.28. For firefighters who were not 9/11 first-responders, the probability of alcohol-related problems is 0.20. Is the following a valid statement? Based on this data, participation in the 9/11 rescue increases the risk of alcohol- related problems by 40%. O invalid O valid