how would I answer this and for expiramental is it within?

14. A researcher is studying the effects of sleep on aggression. The researcher predicts more sleep will lead to less aggression. On Monday night, the researcher had the subjects sleep 9 hours and the following morning play a basketball game where the number of aggressive behaviors was observed. The next night, the same subjects slept 4 hours and then played a basketball game again where the number of aggressive behaviors were observed. Upon analysis, the researchers computed : value was -2.376 with a critical value of 2.210. Answer the following- each question is worth 1 point. a. Is the research hypothesis one tailed or two tailed? b. What is the independent variable in this study? c. What are the levels of the independent variable in this study? d. What is the dependent variable in this study