We want to determine if alcohol has an impact on reaction time. The reaction time of the same person is then measured three times, that is, when they are sober, when they have consumed alcohol and when they have consumed a placebo. Here are the results of five participants.

1 2 3 4 5

Sober: 7 9 6 9 7

Alcohol: 14 13 11 12 11

Placebo: 10 12 8 5 9

a) Formulate the null hypothesis of this research question.

b) Formulate the alternative hypothesis of this research question.

c) Use the appropriate test to answer this research question, showing all of your calculations.

d) What is your decision about the results? If necessary, perform additional tests.

e) Present your results scientifically.