A study is conducted to determine if adults over 50 years old with higher total cholesterol levels are more hostile than those with lower cholesterol levels. A group of 100 adults is randomly selected and their level of hostility as well as their cholesterol levels is recorded.
I. What is the population?
II. What is the sample?
III. Is the study observational or experimental? Justify your answer.
IV. If observational, identify ALL variables. If experimental, identify ALL independent and dependent variables.
V. For each of the variables identified in part IV, list which of the four levels/scales of measurement was used to obtain data on these variables?
VI. Classify each of the variables identified in part IV as either attribute or numerical.