A researcher wants to test the hypothesis that alcohol reduces driver's reaction
time. On a closed driving course, the researcher studies 50 drivers with alcohol in
their system and 50 drivers with no alcohol in their system, while measuring
reaction time in milliseconds. The average reaction time for drivers with alcohol in
their system was 142 milliseconds with a standard deviation of 7.45. The average
reaction time with no alcohol in their system was 134 milliseconds with a standard
deviation of 6.81.
What are your conclusions about the null hypothesis?