A cognitive psychologist expects that reaction times on a simple puzzle task will be impacted by mood. He randomly assigns participants to watch either a happy or a sad film before completing the puzzle and records how long it takes them to finish. Which of the following best describes the hypothesis in this study? Causal hypothesis Predictive hypothesis Dependent variable Untestable hypothesis Question 8 (1 point) A samplen of population can be considered "representative" if it: contains the phenomena of interest. demonstrates sampling bias. reflects the whole population to be studied. is taken systematically from the population.

1. The psychologist assigns participants to watch either a happy or a sad film before doing the puzzle, thus manipulating mood. Because the design involves actively changing an independent variable (mood) to see its effect on reaction time, the hypothesis is testing a causal relationship. **Answer: Causal hypothesis** 2. A representative sample is one in which the characteristics of the sample reflect those of the entire population that is being studied. This means the sample should mirror the key features of the whole population without introducing systematic bias. **Answer: reflects the whole population to be studied.**