A Controlled Experiment

A lab group was given the task of determining the effect of alcohol on reaction time in humans. The test consisted of a computer program that presented an X in the middle of the screen. The participants were told to press the spacebar on the keyboard as soon as the X appeared. The computer's internal clock measured the amount of time between the appearance of the X and the pressing of the spacebar. 30 male volunteers, were split equally in three groups. The results of the experiment are shown in the data table below.

1. Which hypothesis is best supported by the data presented?
   1. Not everyone consumes alcohol.
   2. Amount of alcohol consumed increases reaction time.
   3. Age influences reaction time.
   4. The decrease in reaction time is caused by the consumption of alcohol.
   
   
2. To correctly plot these data, you would place ___ on the X-axis and ___ on the Y-axis.
   1. amount of alcohol consumed; age of the volunteer
   2. amount of alcohol consumed; reaction time
   3. reaction time; amount of alcohol consumed
   4. reaction time; age of volunteer
   
   
3. Which one of the following represents the control group for this experiment?
   1. Group 1
   2. Group 2
   3. Group 3
   4. There is no control group in this experiment
   
   
4. In the described experiment ___ is the independent/experimental variable and ___ is the dependent/measured variable.
   1. amount of alcohol consumed; age of the volunteer
   2. amount of alcohol consumed; reaction time
   3. reaction time; amount of alcohol consumed
   4. reaction time; age of volunteer