Question

you measure brain activity while billie listens to each song. the brain activity you measured is relative to the mean activity across the whole study (i.e., the measurement does not have an absolute zero). what type of data is your measure of brain activity? nominal ordinal interval ratio

Explanation:

• Nominal data is categorical data without any order (e.g., types of fruits). Here, brain - activity data has a numerical nature (relative to the mean), so it's not nominal.
• Ordinal data has an order but no consistent interval between values (e.g., ratings like "poor", "fair", "good"). Brain - activity data (relative to the mean) has a more precise numerical relationship (difference between values can be calculated), so it's not ordinal.
• Interval data has consistent intervals between values and no absolute zero. Since the brain - activity measurement is relative to the mean (no absolute zero) and differences between values are meaningful (e.g., if value \(A = 10\) and value \(B=20\), \(B - A=10\) is a meaningful difference), this fits the definition of interval data.
• Ratio data has a consistent interval and an absolute zero (e.g., height, weight). Since there is no absolute zero in the brain - activity measurement (relative to the mean), it's not ratio data.

Answer:

interval