Final answer:
The data recorded by the scientist, which is the duration of eruptions of the Old Faithful geyser in Yellowstone, is an example of quantitative continuous data.
Step-by-step explanation:
The data recorded by the scientist, which is the duration of eruptions of the Old Faithful geyser in Yellowstone, is an example of quantitative continuous data. This type of data consists of measurements or observations that can be expressed as numerical values, in this case, the length of time for each eruption. Quantitative data can be further classified as either discrete or continuous. Discrete data consists of separate and distinct values, while continuous data can take on any value within a range.