Recent studies seem to indicate that using a mobile phone while driving is dangerous. One reason for this is that a driver's reaction times may slow while he or she is talking on the phone. Researchers measured the reaction times of 143 drivers who owned a mobile phone, 78 drivers on the phone and 65 drivers not on the phone. The reaction times were recorded (in seconds). Can we conclude that the reaction times are slower for drivers using mobile phones? Test using ? = 0.05.